893 Sentences With "binary system" | Random Sentence Generator

It's basically a simple binary system using 0s and 1s.

Also, if the suspected stellified planet is in a binary system, and especially if it is located in a binary system with one or more planets in the habitable zone of its companion, it could be an excellent candidate.

Another possible scenario is that the star was actually part of a binary system.

Alternately, the Earth and Moon formed together as a binary system within the Sun's protoplanetary disk.

It is also a means of wresting back our image from a dominant and binary system.

They use the mathematics of tiny particles, rather than computer logic, to guide their binary system calculations.

"We were very surprised by the total mass of this ancient neutron star binary system," said Scott.

This marks the first time scientists have witnessed the birth of a compact neutron star binary system.

In these situations, pulsars—quickly spinning neutron stars—exist in a binary system along with a companion star.

For many people born with a DSD, the binary system of male and female just doesn't cover it.

But this is a revolutionary moment, and we cannot revert to the ongoing distractions of a binary system.

Ultima Thule is thought to be a close binary system or a contact binary (in which two pieces are touching).

Nix, Styx, Kerberos and Hydra are the tiny (>50 km across) and shiny moons orbiting the Pluto-Charon binary system.

I think that our inclination to use a binary system of cancellation and standom for our favorite celebrities is counterproductive.

It's also known as an eclipsing binary system because one of the stars repeatedly crosses in front of the other.

The first is just a normal pair of black holes in a binary system beaming x-rays directly at Earth.

Cromartie and her team observed this binary system from 2014 to 2019 using the Green Bank Telescope in West Virginia.

Pairs of neutron stars form when two massive stars in a binary system come to the end of their lives.

The former North Star is part of a binary system, meaning it has a much fainter companion star it orbits.

"The binary system KELT-43BC may be what ultimately drove the planet KELT-4Ab so close to its star," Eastman said.

EBLM J0555-57Ab is located about 600 light-years from Earth, and it's part of a unique—and rather lopsided—binary system.

Thankfully, we can find these small stars with planet-hunting equipment, when they orbit a larger host star in a binary system.

"We expect this two-level accretion process to drive the dynamics of the binary system during its mass accretion phase," Alves said.

Novae are explosions that occur on the surface of white dwarf stars sucking up matter from a partner in a binary system.

But its editors wrote that 2016 is the year to break the binary system, especially as controversy swirls around both major-party nominees.

Though rare, some comets consist of multiple pieces, as evidenced by the recent discovery of a binary system bearing the characteristics of a comet.

"Our ideas about planetary formation suggest that that planet could not have formed in the binary system as we see it today," Haswell said.

Each "layer" in the spiral is thought to represent about 800 years, which is the estimated orbital period of the binary system, according to Hubble.

During the flyby, we'll learn if Ultima Thule is a close binary system, a contact binary (in which two pieces are touching), or something else entirely.

According to one of the show's writers, Jane Espenson, the system in question is a double binary system, with the 12 planets orbiting the four stars.

What they found: Scientists now think it's possible the hydrogen ejected by ASASSN-18tb was actually from the white dwarf's other star in the binary system.

" She added, "They didn't know how to process it because, for them, it was being thrown into a binary system of processing it, negative or positive.

Even if ungendering were listed, it would be framed as negative rather than as the rare opportunity it is to finally slip outside the brutal binary system.

Because femininity and sexuality are so heavily filtered through both the male gaze and a binary system of gender, we still haven't haven't separated sexuality and gender presentation.

The Calvin College team, lead by professor Larry Molnar, has been observing the KIC 9832227 binary system since they first heard about it at a conference in 2013.

Artist's impression of the exotic binary system AR Scorpii, with a compact white dwarf star (right) flogging its red dwarf companion with high energy electrons every two minutes.

There's fascinating bits about how the number system (and zero) was resisted by the Romans and how it's very important to calculus and things like the binary system.

Our limited understanding of sex and gender comes from a mainstream medical assessment that looks only at external genitalia and then labels a baby within this binary system.

Cordes' idea adapts the pulsar-lens theory, only in this case, an FRB doesn't need to be in a binary system for the magnification to take place, Main said.

In the case of Alpha Centauri A and B, this binary system has the potential to capture Earth-sized objects—meaning it could snatch rogue planets drifting through interstellar space.

These types of supernovas are thought to come from the explosions of white dwarf stars — the dead remnants of a sun-like star — in a binary system with another star.

On my way out, there was a "binary-code switch" where you can turn on buttons, labeled zero or one for the binary system used in programming, to light them up.

The authors of another paper, who consulted with the researchers who discovered the pattern, suggest the cause could be coming from a neutron star and early OB-type star binary system.

Trans athletes cause more moral panic than cisgender gay athletes, but trans women and trans men still fall into our culture's gender binary system, even as they challenge its violently cruel rigidity.

"The current binary system of employment classification means that either a worker is an employee who is provided significant social benefits or an independent worker who is provided relatively few," he said.

The broadcast was beamed toward the nearest black hole, 1A 0620-00, which lives in a binary system with a fairly ordinary orange dwarf star, his daughter Lucy Hawking said in a statement.

In June 2015, V404 Cygni, a binary system that is comprised of a black hole and an orbiting star slightly smaller than the sun, went through a phase of dramatic brightening for two weeks.

They were able to determine the source of the pulsation because the star varied in observations based on fluctuations in brightness, the angle of the star and how it was oriented in its binary system.

Roughly one in 20 neutron stars ends up in a binary system with another object, be it another neutron star, a regular star, or even a black hole, which is another kind of dead star.

But the object seems to have mostly survived the encounter, which the new study proposes is due to the structural integrity provided by a merged two-star (binary) system hidden deep within its dust cloud.

To put this in perspective, the shortest previous distance between two stars in a binary system hosting planets was 1,000 AU. The planets and their stars were found 154 light-years away in the constellation Libra.

Clarification: A previous version of this article said that the white dwarf binary system could fit within our solar system; more accurately, the binary could fit within the diameter of the planet Saturn, according to the paper.

V404 Cygni, a tumultuous binary system composed of a black hole and a companion star, is located approximately 8,000 light-years from Earth and has the distinction of being the first black hole officially identified in our galaxy.

The black hole is around 3.3 times as massive as the Sun, scientists believe, and is in a binary system called J05215658 that is located about 10,000 light years away in the outer edge of the Milky Way's disk.

Jackson's analysis suggests the odds are slim that this interstellar visitor was ejected from a system featuring a single star, or even a binary system where the stars are located far apart and exerting weak gravitational forces between the two.

The Aquaman actress, 32, spoke at the Making Change On and Off the Screen panel at SXSW Saturday, and explained that her parents were unable to process that her sexuality could be viewed outside a "binary system" of positive or negative.

If the stars that gave rise to these black holes had been lifting and evolving together in a binary system, their spins should be aligned, spinning on parallel axes like a pair of gold medal skating dancers at the Olympics, Dr. Reitze explained.

It's also possible that we are witnessing a binary system containing a massive star and a super-dense stellar core known as a neutron star, according to a study published on arXiv on Wednesday by a separate team that looked at the same data.

For Leah Juliett, a 20-year-old New York-based activist and the founder of the March Against Revenge Porn, she identifies as both non-binary (not identifying with the gender binary system) and gender-fluid, and she uses the pronouns she/her and they/them.

"Beauty" and "beast" are not here a binary system of opposites but a correlation: the two words are interchangeable not only in terms of their meaning but relation to the world at a given moment — the beautiful is sometimes terrible, and the terrible is sometimes beautiful.

"This leads to the intriguing possibilities that the old binary system we've discovered formed differently to those observed in the Milky Way, and that neutron star binaries this massive may not be detectable by current telescope surveys," said Susan Scott, study co-author from the Australian National University.

This isn't the first time scientists have measured the mass of a white dwarf either, but other methods usually require some theoretical model and other measurements or a much closer binary system than this one, astronomer Pier-Emmanuel Tremblay from the University of Warwick in the United Kingdom told Gizmodo.

The answer is very complex but amply visible (and readable) in the exhibition: Unorthodox is not about orthodox/unorthodox as a binary system, but feeds from the Jewish tradition's postulate that truth, rather than being achieved at the end of a long chain of formal logic, requires a dialogical relationship between the life of the mind and the life of the community.

Instagram Verified Accounts: The System Is Broken Taylor Lorenz says Twitter and Instagram should overhaul their verification systems: Rather than have a binary system where users are either check-marked or not—and the lucky few get access to special perks that all users would likely appreciate—Twitter, Instagram, and the like should rebuild the whole system and adopt new features to meet users' needs.

You've got supportive commands that use policy in a way it was meant to be used, as a kind of checklist to get people from one box to the other box within the system because the military is very much a gender binary system: you're male or female and it's what do you need to do to get everything from one side of that aisle to the other.

A common envelope is sometimes confused with a contact binary. In a common envelope binary system the envelope does not generally rotate at the same rate as the embedded binary system; thus it is not constrained by the equipotential surface passing through the L2 Lagrangian point. In a contact binary system the shared envelope rotates with the binary system and fills an equipotential surface.

Hoveyda'group hydroalumination method Another method doesn't involve hydrometalation but hydroiodation with I2/hydrophosphine binary system, which was developed by Ogawa's group.Kawaguchi, Shin-ichi, and Akiya Ogawa. "Highly Selective Hydroiodation of Alkynes Using an Iodine− Hydrophosphine Binary System." Organic Letters 12.9 (2010): 1893-1895.

In industry the butanol-water mixture is separated with this technique. Image:conti hetero 1.png At the previous case the binary system forms already a heterogeneous azeotrope. The other application of the heteroazeotropic distillation is the separation of a binary system (A-B) forming a homogeneous azeotrope.

HU Aquarii (abbreviated HU Aqr) is an eclipsing binary system approximately 570 light-years away from the Sun, forming a cataclysmic variable of AM Herculis-type. The two stars orbit each other every 2.08 hours and the ultra- short binary system includes an eclipsing white dwarf and red dwarf.

This binary system has also led to the development of special Ubiquity Dice, which are not detailed below.

HD 106515 AB is a wide binary system which was first observed by Jérôme de Lalande in 1795.

Gary Urton has suggested that the quipus used a binary system which could record phonological or logographic data.

HD 112014 is a spectroscopic binary system in the constellation Camelopardalis, consisting of two A-class main-sequence stars.

Mu Andromedae has recently been found to be a binary system. The two stars orbit each other every 550.7 days.

BP Crucis (x-ray source GX 301-2) is an X-ray binary system containing a blue hypergiant and a pulsar.

The brighter yellow star (actually itself a very close binary system) makes a striking colour contrast with its fainter blue companion.

Lapointe was also a mathematician, and developed the bibi-binary system (also known in French as the système Bibi) in 1971.

Kepler-14b's host star is the primary (A) component of the Kepler-14 binary system. However, because the binary system is so closely knit, it was impossible at the time of Kepler-14b's discovery to distinguish the characteristics of each individual star. If the Kepler-14 system was an individual star, it would be an F-type star.

Another theory is that runaways of this mass and velocity can be produced by an encounter between a massive single star and a close binary system. Such an encounter is expected to send the binary system in the opposite direction to the single star, and no such massive binary has been found corresponding to BD+43 3654.

In October 2018, it was reported that Antenor is likely a binary system. If confirmed, it would be 5th known binary Jupiter trojan.

Simulated animation of the Moshup binary system. The simulation speed is approx. 12,000 times real-time. Moshup has a minor-planet moon orbiting it.

' is a trans-Neptunian object and binary system of the Kuiper belt, located in the outermost region of the Solar System. The cubewano was discovered at the Mauna Kea Observatories on 27 July 2001, by JJ Kavelaars, Jean-Marc Petit, Brett Gladman, and Matthew Holman. Later in 2001, Kavelaars discovered that it is a binary system. The diameter of the two components are estimated at about and .

58534 Logos, or as a binary system (58534) Logos-Zoe, is a trans-Neptunian object and binary system from the classical Kuiper belt, approximately . The bright cubewano belonged to the cold population and has a 66-kilometer sized companion named Zoe. The system mass is . In the Gnostic tradition, Logos and Zoe are a paired emanation of the deity, and part of its creation myth.

The planetary nebula is asymmetric, which is the result of there being not a single star, but a binary system at the heart of the nebula.

It is a red clump star and the primary component of a suspected binary system, with the pair having an angular separation of 0.2 arc seconds.

Together with Orthodoxy, this book is regarded as the finest flagship of his corpus of moral theology; a binary system in the cosmos of western philosophy.

This pair may form an eclipsing binary system with a period of 785 days (2.15 years), resulting in a magnitude change of 0.12 during each eclipse.

In 1996, 107 years after their discovery, the components of the Mizar A binary system were imaged in extremely high resolution using the Navy Prototype Optical Interferometer.

The aforementioned I Ching that Leibniz encountered dates from the 9th century BC in China. The binary system of the I Ching, a text for divination, is based on the duality of yin and yang. Slit drums with binary tones are used to encode messages across Africa and Asia. The Indian scholar Pingala (around 5th–2nd centuries BC) developed a binary system for describing prosody in his Chandashutram.

Both stars are light-years away, and based on this distance have a minimum separation of approximately 2,700 astronomical units, an unusually wide separation for a binary system.

This is the first time that planets have been found in both components of a wide binary system. The HD 20781 do not have a noticeable starspot activity.

Brightness changes in the light curve that have the same period as the orbital period of the binary system, are always assumed to be due to pulsed accretion.

A close binary system of two white dwarfs can radiate energy in the form of gravitational waves, causing their mutual orbit to steadily shrink until the stars merge.

A ternary computer (also called trinary computer) is a computer that uses ternary logic (three possible values) instead of the more popular binary system ("Base 2") in its calculations.

Subsequently, it was classified as a RS Canum Venaticorum and BY Draconis variable by an automated program. This is probably a binary system with an unseen companion. It is physically associated with the likely binary system HIP 19255, with the two pairs orbiting each other over a time scale of around a million years. The components of HIP 19255 have an angular separation of 3.87″ and the two components orbit each other every 590 years.

While Leibniz was examining other cultures to compare his metaphysical views, he encountered an ancient Chinese book I Ching. Leibniz interpreted a diagram which showed yin and yang and corresponded it to a zero and one. More information can be found in the Sinophile section. Leibniz may have plagiarized Juan Caramuel y Lobkowitz and Thomas Harriot, who independently developed the binary system, as he was familiar with their works on the binary system.

In astronomy, a common envelope (CE) is gas that contains a binary star system. The gas does not rotate at the same rate as the embedded binary system. A system with such a configuration is said to be in a common envelope phase or undergoing common envelope evolution. During a common envelope phase the embedded binary system is subject to drag forces from the envelope which cause the separation of the two stars to decrease.

The documentary visits the science fiction world of Helliconia, which was created by Brian Aldiss. It's a binary system and they show how life can adapt to having two suns.

RS Ophiuchi is a system consisting of a white dwarf with a red giant companion. The stars are in a binary system with an orbital period of around 454 days.

This single-degenerate white dwarf with normal star binary system represents one of two mechanisms for producing a type-Ia supernova, the other being double-degenerate two white dwarf binary stars.

GS 2000+25 is an X-ray binary system in the constellation Vulpecula, consisting of a late K-type star and a black hole. It is also an X-ray nova.

Because of this observation, the black hole most likely was not formed from direct collapse of a massive star, but rather from the supernova of a metal-rich star. The two objects in the binary system were probably not born together as a supernova would likely eject the companion from the system. The most likely theory as to how the black hole became part of the binary system is that XTE J1118+480 was formed in the central galactic halo. The black hole primary was the result of a "kick" from the supernova explosion of a massive star in the early galaxy and travelled through the galaxy and into the central galactic halo, becoming a binary system with its present-day companion.

This is a single-lined spectroscopic binary system a period of in a close, circular orbit. The pair form an eclipsing binary system that decreases from magnitude 14.9 down to 20.2, once per orbit. This object, along with AM Herculis, define a class of cataclysmic variables known as polars. The pair consist of a low mass white dwarf with a strong magnetic field, interacting with a low–mass main sequence star that has filled its Roche lobe.

HR 273 is a chemically peculiar spectroscopic binary system in the northern circumpolar constellation of Cassiopeia. It has an apparent visual magnitude of 5.9 making it faintly visible to the naked eye from dark suburban skies. Parallax measurements with the Hipparcos spacecraft put this system at a distance of roughly 350 light years. The primary, HR 273 A, is an Ap star and the secondary is an Am star, making this a very unusual binary system.

In 2017, more accurate analysis found it to be a binary system made up of two substellar objects of spectral class≥Y1 in orbit less than one astronomical unit from each other.

LS I +61 303 is a microquasar, a binary system containing a massive star and a compact object. The compact object is a black hole candidate and is around 7,000 light-years away.

Pluto and its moon Charon are often described as a binary system. When binary minor planets are similar in size, they may be called "binary companions" instead of referring to the smaller body as a satellite. Good examples of true binary companions are the 90 Antiope and the 79360 Sila–Nunam systems. Pluto and its largest moon Charon are sometimes described as a binary system because the barycenter (center of mass) of the two objects is not inside either of them.

This is a spectroscopic binary system with a close circular orbit taking just 0.945 days to complete. Despite their proximity, this does not appear to be a contact binary system. The orbital plane of the two stars lies near the line of sight, so they form an Algol-type eclipsing binary. The first component of the system is an A-type main sequence star with a stellar classification of A2 V. Its companion is giant star with a classification of K0 III.

The rotational axis of the binary system is directed approximately towards Earth at an estimated inclination of 0 to 16 degrees. This provides a fortunate viewing angle for observing the binary system and its dynamics. WR 104 is surrounded by a distinctive dusty Wolf–Rayet nebula over 200 astronomical units in diameter formed by interaction between the stellar winds of the two stars as they rotate and orbit. The spiral appearance of the nebula has led to the name Pinwheel Nebula being used.

For a visual binary system, measurements taken need to specify, in arc-seconds, the apparent angular separation on the sky and the position angle which is the angle measured eastward from North in degrees of the companion star relative to the primary star. Taken over a period of time, the apparent relative orbit of the visual binary system will appear on the celestial sphere. The study of visual binaries reveal useful stellar characteristics: Masses, densities, surface temperatures, luminosity, and rotation rates.

IRAS 08544−4431 is a binary system surrounded by a dusty ring in the constellation of Vela. The system contains an RV Tauri variable star and a more massive but much less luminous companion.

1509 Esclangona, provisional designation , is a rare-type Hungaria asteroid and binary system from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. It is named after French astronomer Ernest Esclangon.

Tyson is an asynchronous binary asteroid, with a minor planet moon, designated in its orbit. The satellite has a rotation period of 3.862 hours. No other physical properties for this binary system has been published.

SDSS J1416+1348 (full designation is SDSS J141624.08+134826.7) is a nearby wide binary system of two brown dwarfs, located in constellation Boötes. The system consists of L-type component A and T-type component B.

Such follow-up observations are estimated to reduce the chance of such background objects to less than 0.01%. Additionally, spectra of the KOIs can be taken to see if the star is part of a binary system.

FU Tauri is a brown dwarf binary system in the constellation of Taurus about away. The secondary is very close to the lower limit for brown dwarfs and several databases list it as a distant massive exoplanet.

NN Serpentis (abbreviated NN Ser) is an eclipsing post-common envelope binary system approximately 1670 light-years away. The system comprises an eclipsing white dwarf and red dwarf. The two stars orbit each other every 0.13 days.

Astrometric binaries are objects that seem to move around nothing as their companion object cannot be identified, it can only be inferred. The companion object may not be bright enough or may be hidden in the glare from the primary object. A related classification though not a binary system is optical binary, which refers to objects that are so close together in the sky that they appear to be a binary system, but are not. Such objects merely appear to be close together, but lie at different distances from the Solar System.

BW Circini is a low mass X-ray binary system, comprising a black hole of around 8 solar masses and a yellow G0III-G5III subgiant star. X-ray outbursts were recorded in 1987 and 1997, and possibly 1971–72.

42 (1976), pp. 126 -130.Y.K. Lee and C.S. Choi, Driving Force for γ→ε Martensitic Transformation and Stacking Fault Energy of γ in Fe- Mn Binary System, Metallurgical and Materials Transactions A, Vol. 31A (2000), pp. 355-360.

The group is dominated by two close B-Type stars, HD 250289 (B2III) and HD 250290 (B3I). With the two stars sharing the same proper motion and radial velocity it is likely that the two constitute a binary system.

SU Aurigae's proper motion and distance is similar to AB Aurigae, a better known pre-main-sequence star, meaning that the two may form a very wide binary system; if not, they are still in the same star association.

WISEPC J045853.90+643451.9 (designation is abbreviated to WISE 0458+6434) is a binary system of two (A and B) ultracool brown dwarfs of spectral classes T8.5 and T9.5, respectively, located in constellation Camelopardalis at approximately 47 ly from Earth.

QS Virginis (abbreviated QS Vir) is an eclipsing binary system approximately 163 light-years away from the Sun, forming a cataclysmic variable. The system comprises an eclipsing white dwarf and red dwarf that orbit each other every 3.37 hours.

Superhumps were first seen in SU Ursae Majoris (SU UMa) stars, a subclass of dwarf novae, at times when the binary system underwent a superoutburst, which is an unusually strong outburst (increase in brightness) caused by an increased accretion rate.

HD 191104 is a star system in the equatorial constellation of Aquila. Two of the components form a close spectroscopic binary system, while a third star, also thought to be a spectroscopic binary, orbits the pair at a greater distance.

2486 Metsähovi, provisional designation , is a stony asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 22 March 1939, by Finnish astronomer Yrjö Väisälä at the Turku Observatory.

Its companion, ζ Capricorni B is a hydrogen-rich white dwarf. It is about as massive as the Sun, and its temperature is 23,000 K. The ζ Capricorni binary system is approximately 390 light years from Earth, based on its parallax.

SCR 1845−6357 is a binary system, about 12.6 light-years away in the constellation Pavo. The primary is a faint red dwarf. It has a brown dwarf companion. The primary red dwarf was discovered in 2004 by Hambly et al.

Plaskett's Star , also known as HR 2422 and V640 Monocerotis, is a spectroscopic binary at a distance of around 6600 light-years. It is one of the most massive binary stars known, with a total mass of around one hundred times that of the Sun. Indeed, it was long thought to be the most massive known binary system, but evidence collected between 1996–2005 demonstrated that Eta Carinae, which was previously thought to be a massive individual star, is a binary system. This system is named after John Stanley Plaskett, the Canadian astronomer who discovered its binary nature in 1922.

In the past the inner pair, designated component A, has been described as an eclipsing binary system, showing a primary minimum of 6.05 and a secondary minimum of 6.04. They have an orbital period of 0.841658 days, zero eccentricity, and an inclination of 19 degrees. However, Bruno Cester argued that the apparent eclipses are not real, and were caused by seeing different portions of distorted-shaped stars in a near contact binary system. As of 2017, it is classified as a rotating ellipsoidal variable and possibly a W Ursae Majoris- type system, although not in physical contact.

Gorjup is a paired asteroid with . It is thought that asteroid pairs are formed by a single parent body, that broke up into a proto-binary system due to its rotation. Soon after, such systems disrupt under their own internal dynamics into pairs.

In May 2017, photometric observations by Brian Warner and Alan Harris revealed that is a synchronous binary system with a secondary component orbiting around the system barycenter every 40.572 hours. The secondary has been confirmed by radar observations. Its provisional designation is .

SS 433 is one of the most exotic star systems observed. It is an eclipsing X-ray binary system, with the primary most likely a black hole, or possibly a neutron star.The Quest for SS433, David H. Clark. New York: Viking, 1985.

The most recent studies propose, in summary, a model of binary system of hypernova (BdHN I) with two neutron stars, where one of them collapses in a black hole, surrounded by an accretion disk and from whose poles the GRB is launched.

Daoist Bagua The bit string is not the only type of binary code: in fact, a binary system in general, is any system that allows only two choices such as a switch in an electronic system or a simple true or false test.

' is a trans-Neptunian object and binary system that belongs to the scattered disc (like Eris). Its discovery was announced on 31 March 2014. It has an absolute magnitude (H) of 3.2. is a binary object, with two components approximately and in diameter.

In 2004, the U.S Palmer Divide Observatory, Colorado, reported the discovery of an asteroid moon making the asteroid a binary system. The moon's orbital period has since been measured to take 30.292, 30.34 and 30.35 hours, respectively, for a full orbit around its primary.

Eggleton and Tokovinin (2008) catalogued this as a single star, albeit with some uncertainty. However, Chini et al. (2012) listed it as a single-lined spectroscopic binary system. The visible component of V343 Carinae has a stellar classification of B1.5III, matching a massive blue giant.

WR 46 has been suspected to be a binary system with an OB companion. The orbital period of the system has been reported at 0.311 days and 0.329 days. Most recent research refutes the idea of a companion, instead favoring the single WN star theory.

EZ Canis Majoris (abbreviated to EZ CMa, also designated as WR 6) is binary system in the constellation of Canis Major. The primary is a Wolf-Rayet star and it is one of the ten brightest Wolf-Rayet stars, brighter than apparent magnitude 7.

A binary system is a system of two astronomical bodies which are close enough that their gravitational attraction causes them to orbit each other around a barycenter (also see animated examples). More restrictive definitions require that this common center of mass is not located within the interior of either object, in order to exclude the typical planet–satellite systems and planetary systems. The most common binary systems are binary stars and binary asteroid, but brown dwarfs, planets, neutron stars, black holes and galaxies can also form binaries. A multiple system is like a binary system but consists of three or more objects such as for trinary stars and trinary asteroids.

The phase ends either when the envelope is ejected to leave the binary system with much smaller orbital separation, or when the two stars become sufficiently close to merge and form a single star. A common envelope phase is short-lived relative to the lifetime of the stars involved. Evolution through a common envelope phase with ejection of the envelope can lead to the formation of a binary system composed of a compact object with a close companion. Cataclysmic variables, X-ray binaries and systems of close double white dwarfs or neutron stars are examples of systems of this type which can be explained as having undergone common envelope evolution.

Alpha Centauri is a triple star system, with its two main stars, Alpha Centauri A and Alpha Centauri B, being a binary component. The AB designation, or older A×B, denotes the mass centre of a main binary system relative to companion star(s) in a multiple star system. AB-C refers to the component of Proxima Centauri in relation to the central binary, being the distance between the centre of mass and the outlying companion. Because the distance between Proxima (C) and either of Alpha Centauri A or B is similar, the AB binary system is sometimes treated as a single gravitational object.

3905 Doppler, provisional designation , is a stony asteroid and binary system from the middle region of the asteroid belt, approximately 8 kilometers in diameter. The asteroid was discovered on 28 August 1984, by Czech astronomer Antonín Mrkos at Kleť Observatory and named after physicist Christian Doppler.

The photometric observations also revealed, that Belgica is a binary system with an asteroid moon, approximately 36% the diameter of its primary, orbiting it every hours. Johnston's archive derives a diameter of 3.53 kilometers and estimates a semi-major axis of 34 kilometer for the moon.

Another system is PSR B1620−26, where a circumbinary planet orbits a neutron star-white dwarf binary system. Also, there are several unconfirmed candidates. Pulsar planets receive little visible light, but massive amounts of ionizing radiation and high-energy stellar wind, which makes them rather hostile environments.

Observations of the HST revealed ongoing activity in this binary system. The combined features of this binary asteroid - wide separation, near-equal component size, high eccentricity orbit, and comet-like activity also make it unique among the few known binary asteroids that have a wide separation.

HD 142022 is a binary system, a component of which is a sunlike star with a massive planet with an orbital period of 1928 ± 46 days. HD 212301 is a yellow-white main sequence star with a hot jupiter that completes an orbit every 2.2 days.

', provisional designation , is a trans-Neptunian object and binary system from the classical Kuiper belt, located in the outermost region of the Solar System. It was discovered by American astronomer Marc Buie at Kitt Peak Observatory on 7 November 2002. The primary measures approximately in diameter.

HIPASS J1712-64 is an isolated extragalactic cloud of neutral hydrogen with no associated stars. The cloud is a binary system and is not dense enough to form stars. HIPASS J1712-64 was probably ejected during an interaction between the Magellanic clouds and the Milky way.

Artistic simulation of Kepler-14b and its host star. Kepler-14b is the sole planet discovered in the Kepler-14 system to date. The planet orbits the primary star in the Kepler-14 binary system. Kepler-14b is estimated to have 8.40 Jupiter masses and 1.136 Jupiter radii.

Collisions occur with greater frequency in the dense core regions of globular clusters (cf. blue stragglers). A likely scenario is a collision with a binary star system, or between two binary systems containing white dwarfs. This collision can leave behind a close binary system of two white dwarfs.

3868 Mendoza, provisional designation is a stony Vestian asteroid and binary system from the inner regions of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 24 September 1960, by astronomers Cornelis Johannes van Houten, Ingrid van Houten-Groeneveld and Tom Gehrels at Palomar Observatory.

In a binary system, the brighter object is referred to as primary, and the other the secondary. They are also classified based on orbit. Wide binaries are objects with orbits that keep them apart from one another. They evolve separately and have very little effect on each other.

The spatial dimension of this cluster is about across. It has an estimated mass of , of which about 24% is interstellar matter. A Delta Cephei type variable star designated U Sagittarii is a member of this cluster, as are two red giants, one of which is a binary system.

4492 Debussy (prov. designation: ) is a dark and elongated background asteroid and binary system from the intermediate asteroid belt, approximately in diameter. It was discovered on 17 September 1988, by Belgian astronomer Eric Elst at Haute-Provence Observatory in France. It was later named after French composer Claude Debussy.

3951 Zichichi, provisional designation , is a stony Florian asteroid and binary system from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 12 February 1986, by staff members at the San Vittore Observatory near Bologna, Italy, and named after physicist Antonino Zichichi.

4765 Wasserburg (prov. designation: ) is a bright Hungaria asteroid, suspected binary system and asteroid pair from the innermost regions of the asteroid belt, approximately in diameter. It was discovered on 5 May 1986, by American astronomer Carolyn Shoemaker at Palomar Observatory, and later named after geologist Gerald J. Wasserburg.

Centaurus X-3 is located in the galactic plane about 5.7 kiloparsecs away, towards the direction of the Carina–Sagittarius Arm, and is a member of an occulting spectroscopic binary system. The visible component is Krzeminski's Star, a supergiant; the X-ray component is a rotating, magnetized neutron star.

HD 33636 is a binary system located approximately 94 light-years away in Orion constellation. The visible member HD 33636 A is a 7th magnitude yellow main- sequence star. It is located at a distance of 91.6 light years from Earth. It has a metallicity of −0.05 ± 0.07.

In arithmetic, a complex-base system is a positional numeral system whose radix is an imaginary (proposed by Donald Knuth in 1955) or complex number (proposed by S. Khmelnik in 1964 and Walter F. Penney in 1965W. Penney, A "binary" system for complex numbers, JACM 12 (1965) 247-248.).

OY Carinae (abbreviated OY Car) is an eclipsing binary system approximately 277 light-years away from the Sun, classed as cataclysmic variable. The system comprises an eclipsing white dwarf and red dwarf that orbit each other every 1.51 hours, and possibly a yet unconfirmed third low-mass (substellar?) companion.

Most Am stars form part of a binary system in which the rotation of the stars has been slowed by tidal braking. The best-known metallic-line star is Sirius (α Canis Majoris). The following table lists some metallic-line stars in order of descending apparent visual magnitude.

Benedetto Castelli, one of the Galileo's colleagues in the 17th century, observed Mizar through a telescope and realized that it was a binary system: Mizar A and Mizar B. Then, throughout the 19th century and the beginning of the 20th century, with the help of spectroscopy, scientists showed that Mizar A and B were both binary systems. In 1908, the Alcor-Mizar system was the first 5-star system ever discovered. In 2009, Eric Mamajek and his colleagues from the University of Rochester, while searching for exoplanets, discovered that Alcor was also a binary system, making the Alcor and Mizar a 6-star system. The same conclusion was independently found by Ben Oppenheimer from the American Natural History Museum.

Hubble images of Patroclus and Menoetius orbiting each other, from May to June 2017 Artist's conception of Patroclus and Menoetius orbiting around their center of mass, occasionally eclipsing one another Artist's impression of the Patroclus-Menoetius binary system In 2001, it was discovered that Patroclus is a binary system, made up of two components with of roughly similar size. It is one of 18 binary Trojan asteroids known to exist. In 2006, accurate measurements of the orbit from the Keck Laser guide star adaptive optics system were reported. It was estimated that the two components orbit around their center of mass in days at a distance of in a roughly circular orbit.

2013, work in progress # A low mass binary: One of the binary system observed by CoRoT is of particular interest since the less massive component is a late M star of 0.23 M⊙ with an estimated effective temperature of about 3000 K.Gandolfi, D. et al. 2013, work in progress The primary component is a 1.5 M⊙ star MS star. # A beaming effect in a binary: A binary system observed by CoRoT showed out of eclipses variations which were interpreted as a beaming effect (also called Doppler boosting). This effect results from the variation in brightness of source approaching or moving away from the observer, with an amplitude proportional to the radial velocity divided by the speed of light.

Epsilon Aurigae (ε Aurigae, abbreviated Epsilon Aur, ε Aur) is a multiple star system in the northern constellation of Auriga. It is an unusual eclipsing binary system comprising an F0 supergiant (officially named Almaaz , the traditional name for the system) and a companion which is generally accepted to be a huge dark disk orbiting an unknown object, possibly a binary system of two small B-type stars. The distance to the system is still a subject of debate, but data from the Gaia spacecraft puts its distance at around light years from Earth. Epsilon Aurigae was first suspected to be a variable star when German astronomer Johann Heinrich Fritsch observed it in 1821.

In the 1990s, he and his research group, including Rudy Wijnands, discovered the first millisecond X-ray pulsar in a binary system, SAX J1808.4-3658, a neutron star spinning around its axis more than 400 times per second. The discovery of this superfast spinning neutron star attracted great international attention.

KOI-256 is a double star located in the constellation Cygnus approximately from Earth. While observations by the Kepler spacecraft suggested the system contained a gas giant exoplanet orbiting a red dwarf, later studies determined that KOI-256 was a binary system composed of the red dwarf orbiting a white dwarf.

4029 Bridges, provisional designation , is a stony asteroid and binary system from the middle regions of the asteroid belt, approximately 8 kilometers in diameter. It was discovered on 24 May 1982, by American astronomer Carolyn Shoemaker at Palomar Observatory, California, and named after American USGS planetary cartographer Patricia M. Bridges.

3073 Kursk, provisionally known as , is a stony Florian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 4.7 kilometers in diameter. It was discovered on 24 September 1979, by Soviet astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula.

EQ Pegasi is a nearby binary system of two red dwarfs. Both components are flare stars, with spectral types of M4Ve and M6Ve respectively, and a current separation between the components of 5.8 arcseconds. The system is at a distance of 20.4 light-years, and is 950 million years old.

In 2010, Qian et al. announced the detection of a third body of planetary mass around the eclipsing binary system. The presence of a third body had already been suspected in 2002. The object is roughly 6 times more massive than Jupiter and is located 8.6 AU from the binary.

There is disagreement over the properties of this system. Petrie (1939) classified two components as class A0 and A2 with a visual magnitude difference of 1.5. Batten et al. (1989) catalogued it as a double-lined spectroscopic binary system with an orbital period of four days and an eccentricity of 0.02.

Scott Roth of the west coast division of Unimation implemented an interface to the Machine Intelligence Corporation (MIC) vision system VS-100 in early 1981. It was a binary system using blob (connectivity) analysis. Unimation’s first vision system was called Univision I for Puma robots. Carlisle, Brian and Roth, Scott.

5426 Sharp, provisional designation , is a bright Hungaria asteroid and suspected binary system from the inner regions of the asteroid belt, approximately 2–3 kilometers in diameter. It was discovered on 16 February 1985, by American astronomer Carolyn Shoemaker at Palomar Observatory, California, and named after American geologist Robert P. Sharp.

HR 4729 was first observed in 1829, as a companion to α Crucis, by James Dunlop from Paramatta in New South Wales. As early as 1916, HR 4729 was reported to have a variable radial velocity indicating a likely binary system, but the orbital elements were not calculated until 1979.

Several rotational lightcurves of Welther have been obtained from photometric observations since 2001. Analysis of the best-rated lightcurves gave a rotation period of 3.5973 hours with a brightness amplitude of 0.22 and 0.21 magnitude, respectively (). The observing French amateur astronomers also suspected the asteroid to be a binary system.

2478 Tokai, provisionally designated , is a stony Florian asteroid and binary system from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 4 May 1981, by Japanese astronomer Toshimasa Furuta at Tōkai Observatory (), Japan. The asteroid was named after the city of Tōkai.

Planets that orbit just one star in a binary system are said to have "S-type" orbits, whereas those that orbit around both stars have "P-type" or "circumbinary" orbits. It is estimated that 50–60% of binary systems are capable of supporting habitable terrestrial planets within stable orbital ranges.

A minor-planet moon orbiting Edwardolson was discovered in 2005, making it a binary system. The satellite has a fairly short orbital period of 17 hours, 47 minutes, and 2 seconds ( hours), and an estimated mean-diameter ratio of , which would give the satellite a diameter of approximately 1.0 to 1.3 kilometers.

6708 Bobbievaile, provisional designation ', is a stony background asteroid and asynchronous binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 4 January 1989, by Australian astronomer Robert McNaught at the Siding Spring Observatory in New South Wales, Australia. It is named after Bobbie Vaile.

21436 Chaoyichi provisional designation , is a background asteroid and binary system from the inner region of the asteroid belt, approximately 2 kilometers in diameter. It was discovered on 31 March 1998, by astronomers of the Lincoln Near-Earth Asteroid Research at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, United States.

HD 213429 is a spectroscopic binary system in the equatorial constellation of Aquarius. It has a combined apparent magnitude of 6.16 and is located around 83 light years away. The pair orbit each other with a period of 631 days, at an average separation of 1.74 AU and an eccentricity of 0.38.

Feige 55 is a hot white dwarf approximately 650 light-years away from the Sun in the constellation of Ursa Major. The star is likely a post-AGB star with relatively high luminosity for a standard white dwarf. It is also in a close binary system with orbital period of 1.4933 days.

DP Leonis (abbreviated DP Leo) is an eclipsing binary system approximately 1304 light-years away from the Sun, probably a cataclysmic variable star of the AM Herculis-type also known as polars. The system comprises an eclipsing white dwarf and red dwarf in tight orbit (nearly 1.5 hours) and an extrasolar planet.

Also in 2011, the momentum of 15-M collects for the International Day of Action for Trans Depathologization to vindicate the social space for other identities that did not fit within the gender binary system. Every October, various activities included in Trans October (Octubre Trans) are organized to question heteropatriarchy and pink capitalism.

IGR J17091 is a stellar mass black hole with a mass between 3 and 10 . It is a binary system in which a star orbits the black hole. Its small size may make it a candidate for the smallest black hole discovered. However, as of 2017 its mass was described as "unknown".

2074 Shoemaker, provisional designation , is a stony Hungaria asteroid, Mars- crosser and suspected synchronous binary system from the innermost regions of the asteroid belt, approximately 4 kilometers in diameter. It was discovered on 17 October 1974, by astronomer Eleanor Helin at the Palomar Observatory. She named it after American astronomer Eugene Shoemaker.

4217 Engelhardt, provisional designation , is a stony Phocean asteroid and a potentially binary system from the inner regions of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 24 January 1988, by American astronomer Carolyn Shoemaker at Palomar Observatory in California, and later named after German mineralogist Wolf von Engelhardt.

U Mon is a binary system with a dusty ring surrounding both stars. The companion cannot be observed directly or in the spectrum. Its existence is inferred by radial velocity changes as it orbits every 2,597 days. This is approximately the same time as the long secondary period that modulates the brightness variations.

Xi Tauri (ξ Tau, ξ Tauri) is a hierarchical quadruple system in the constellation Taurus. Xi Tauri is a spectroscopic and eclipsing quadruple star. It consists of three blue-white B-type main sequence dwarfs. Two of the stars form an eclipsing binary system and revolve around each other once every 7.15 days.

The mean distance from its host star is about 8.213 times the measured radius of Kepler-14. The authors of Kepler-14b's discovery paper noted that, had they not discovered that Kepler-14 was indeed a binary system, the parameters for Kepler-14b would have been extremely inaccurate. They noted that other planets discovered using radial velocity measurements might not have accounted for the possibility that their host stars were binary systems; the only way that this was definitely known in the case of Kepler-14 was through the use of high-resolution imaging. If the less prominent portion of the Kepler-14 binary system had not been detected, Kepler-14b's mass would have been incorrect by nearly 60%, and its radius too small by about 10%.

The two components are both of spectral type G5IV with a diameter 2.2 times, and mass 1.2 times that of the Sun, and revolve around each other every 3.2 days. The system is classified as a RS Canum Venaticorum variable, a binary system with prominent starspot activity, and lies 184 ± 5 light-years away. The system emits X-rays, and analysing the emission curve over time led researchers to conclude that there was a loop of material arcing between the two stars. RZ Pyxidis is another eclipsing binary system, made up of two young stars less than 200,000 years old. Both are hot blue-white stars of spectral type B7V and are around 2.5 times the size of the Sun.

The brightest star is WR 25 WR 25 is a binary system in the central portion of the Carina Nebula, a member of the cluster. The primary is a Wolf–Rayet star, possibly the most luminous star in the galaxy. The secondary is hard to detect but thought to be a luminous OB star.

Orbital decay for PSR1913+16: time shift in seconds, tracked over three decades.A figure that includes error bars is fig. 7 in According to general relativity, a binary system will emit gravitational waves, thereby losing energy. Due to this loss, the distance between the two orbiting bodies decreases, and so does their orbital period.

It is a suspected rotating ellipsoidal variable with a period of 0.64 days and an amplitude of 0.07 magnitude. Confirmation would indicate that this is a close binary system. It has an estimated age of around 57 million years. In Chinese, (), meaning Son, refers to an asterism consisting of λ Columbae and β Columbae.

5474 Gingasen, provisional designation , is a Vestian asteroid and suspected binary system from the inner regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered on 3 December 1988, by Japanese amateur astronomers Tetsuya Fujii and Kazuro Watanabe at Kitami Observatory, Japan. It is named for the "Gingasen" railroad track in Japan.

In October 2018, Stephens, in collaboration with Brian Warner and several other European observers including Amadeo Aznarand / and Vladimir Benishek at Belgrade Observatory, reported that Antenor is likely a binary system. An orbital period for the suspected minor-planet moon could not be determined. If confirmed, it would be 5th known binary Jupiter trojan.

LL Pegasi (AFGL 3068) is a Mira variable star surrounded by a pinwheel-shaped nebula, IRAS 23166+1655, thought to be a preplanetary nebula. It is a binary system that includes an extreme carbon star. The pair is hidden by the dust cloud ejected from the carbon star and is only visible in infrared light.

HR 9038 is a triple star system located thirty-five light-years away, in the constellation Cepheus. Component A is a spectroscopic binary system with an orbital period of 7.753 days and a combined stellar classification of K3 V. Component B is a red dwarf star that orbits the primary pair every 290 years.

HD 20781 is a star which is part of a wide binary system with HD 20782. The companion star has a very large angular separation of 252 arcsec, corresponding to 9080 AU at the distance of HD 20782.Properties of planets in binary systems. Both stars possess their own planetary systems in S type orbits.

4U 0614+091 is a low-mass X-ray binary star system which features a neutron star and a low-mass companion star. The binary system lies 10,000 light-years away in Orion. It produces jets like a microquasar, the first time an object other than a black hole has been shown to produce jets.

BD Camelopardalis is a naked-eye example of an extrinsic S star. It is a slow irregular variable in a symbiotic binary system with a hotter companion which may also be variable. The Mira variable Chi Cygni is an intrinsic S star. When near maximum light, it is the sky's brightest S-type star.

2691 Sersic, provisional designation , is a stony Florian asteroid and binary system from the inner regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered by staff members at the Felix Aguilar Observatory at El Leoncito Complex in Argentina, on 18 May 1974. The asteroid was named after Argentine astronomer José Sersic.

He then became a prolific observer of variable stars, particularly those that were members of a binary system. He continued his observations for over 30 years, and pioneered the study of close binary systems. He published over 100 works on these topics. Between 1891 and 1920 he made over 250,000 observations of 98 variable stars.

XZ Tauri is a binary system approximately 450 light-years away in the constellation Taurus. The system consists of two T Tauri stars orbiting each other about 6 billion kilometers apart (roughly the same distance as Pluto is from the Sun). The system made news in 2000 when a superflare was observed in the system.

Its binary nature was confirmed by the Hubble Space Telescope in September 2016. Both primary and its minor-planet moon are similar in mass and size, making it a true binary system. The components are estimated to measure 1.8 kilometers in diameter, orbiting each other at a wide separation of 104 kilometers every 135 days.

The Mass-Luminosity Relation, University of Tennessee, Astronomy 162: Stars, Galaxies, and Cosmology, lecture notes. Accessed July 18, 2006. With this technique, the masses of the two stars in a binary system are estimated, usually as the mass of the Sun. Then, using Kepler's laws of celestial mechanics, the distance between the stars is calculated.

BAT99-116 (commonly called Melnick 34 or Mk34) is a binary Wolf–Rayet star near R136 in the 30 Doradus complex (also known as the Tarantula Nebula) in the Large Magellanic Cloud. Both components are amongst the most massive and most luminous stars known, and the system is the most massive known binary system.

QS Telescopii is a binary system composed of a white dwarf and main sequence donor star, in this case the two are close enough to be tidally locked, facing one another. Known as polars, material from the donor star does not form an accretion disk around the white dwarf, but rather streams directly onto it.

It has been estimated that at least 10% of white dwarfs have fields in excess of 1 million gauss (100 T). The highly magnetized white dwarf in the binary system AR Scorpii was identified in 2016 as the first pulsar in which the compact object is a white dwarf instead of a neutron star.

Tau5 Eridani, Latinized from τ5 Eridani, is a binary star system in the constellation Eridanus. It is visible to the naked eye with a combined apparent visual magnitude of 4.26. The distance to this system, as estimated using the parallax technique, is around 293 light years. Tau5 Eridani is a double-lined spectroscopic binary system.

Theta Eridani (θ Eridani, abbreviated Theta Eri, θ Eri) is a binary system in the constellation of Eridanus. Its two components are designated θ¹ Eridani, formally named Acamar (the traditional name of the system), and θ² Eridani. The system's distance from the Sun as measured by the Hipparcos astrometry satellite is approximately 120 light-years.

HW Virginis, abbreviated HW Vir, is an eclipsing binary system (of the Algol type), approximately 563 light-years away based on the parallax measured by the Gaia spacecraft, in the constellation of Virgo. The system comprises an eclipsing B-type subdwarf star and red dwarf star. The two stars orbit each other every 0.116795 days.

Pi Virginis (π Vir, π Virginis) is a binary star in the zodiac constellation of Virgo. It is visible to the naked eye with an apparent visual magnitude of 4.64. The distance to this star, based upon parallax measurements, is roughly 380 light years. This is a spectroscopic binary system with a stellar classification of A5V.

3982 Kastel, provisional designation , is a Florian asteroid and a suspected binary system from the inner regions of the asteroid belt, approximately 6.9 kilometers in diameter. It was discovered on 2 May 1984, by Russian astronomer Lyudmila Karachkina at the Crimean Astrophysical Observatory in Nauchnij on the Crimean peninsula. It is named after Soviet astronomer Galina Kastel'.

HD 93205 is a binary system of two large stars. The more massive member of the pair is an O3.5 main sequence star. The spectrum shows some ionised nitrogen and helium emission lines, indicating some mixing of fusion products to the surface and a strong stellar wind. The mass calculated from apsidal motion of the orbits is .

2754 Efimov, provisionally named , is a stony asteroid and binary system from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 13 August 1966, by Russian astronomer Tamara Smirnova at the Crimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula. The asteroid was named after Russian aviator Mikhail Efimov.

4868 Knushevia, provisional designation is a bright Hungaria asteroid and suspected binary system from the innermost regions of the asteroid belt, approximately 2 kilometers in diameter. It was discovered on 27 October 1989, by American astronomer Eleanor Helin at the Palomar Observatory in California, United States. The asteroid was named for the Kyiv University in Ukraine.

3873 Roddy, provisional designation , is a stony Hungarian asteroid, Mars- crosser and suspected binary system, from the innermost regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 21 November 1984, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California, United States. It was named after American astrogeologist David Roddy.

This pair is a double-lined spectroscopic binary system that forms an Algol-like eclipsing binary. The brightness of the system decreases from 6.44 down to 6.53 during the primary eclipse. It has a stellar classification of A0V, which matches an A-type main-sequence star that is generating energy through hydrogen fusion at its core.

A Thorne–Żytkow object is formed when a neutron star collides with another star, typically a red giant or supergiant. The colliding objects can simply be wandering stars. This is only likely to occur in extremely crowded globular clusters. Alternatively, the neutron star could form in a binary system after one of the two stars went supernova.

' is a stony asteroid and binary system, classified as near-Earth object of the Apollo group, approximately 1 kilometer in diameter. It was discovered on 31 October 2005, by astronomers of the Spacewatch survey at the Kitt Peak National Observatory in Arizona, United States. Its minor-planet moon with an orbital period of 40.25 hours was discovered in 2017.

This is a single-lined spectroscopic binary system with an orbital period of and an eccentricity of 0.4. The visible component is an evolved giant star with a stellar classification of K4 III. Its measured angular diameter is . At the estimated distance of the star, this yields a physical size of about 38 times the radius of the Sun.

M39 is at a distance of about from the Sun. This cluster has an estimated mass of and a linear tidal radius of . Of the 15 brightest components, six form binary star systems with one more suspected. HD 205117 is a probable eclipsing binary system with a period of 113.2 days that varies by 0.051 in visual magnitude.

However, neutron stars may have additional properties. They show differential rotation, and can have a magnetic field and exhibit localized explosions (thermonuclear bursts). Whenever such properties are observed, the compact object in the binary system is revealed as a neutron star. The derived masses come from observations of compact X-ray sources (combining X-ray and optical data).

WASP-85 Ab is an exoplanet that orbits WASP-85 A, a star that is part of a binary system. WASP-85 Ab's mass and radius indicate that it has a bulk composition like that of Jupiter. Unlike Jupiter, and similar to other gas giants, it orbits very close to its star, and is classified as a hot Jupiter.

Sila–Nunam was discovered on 4 February 1997 by Jane X. Luu, David C. Jewitt, Chad Trujillo, and Jun Chen at the Mauna Kea Observatory, Hawaii, and given the provisional designation . It was resolved as a binary system in Hubble observations of 22 October 2002 by Denise C. Stephens and Keith S. Noll and announced on 5 October 2005.

Epsilon Aquilae (ε Aql, ε Aquilae) is the Bayer designation for a binary star in the equatorial constellation of Aquila. It has an apparent visual magnitude of 4.02 and is visible to the naked eye. Based upon an annual parallax of 21.05 mas, Epsilon Aquilae lies at a distance of approximately from Earth. This is a spectroscopic binary system.

2006 Polonskaya, provisional designation , is a stony Florian asteroid and asynchronous binary system from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 22 September 1973, by Soviet astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula, and later named after Russian astronomer Elena Polonskaya.

During the photometric observations in February 2009, it was discovered that Seilandfarm is in fact a binary system. Its minor-planet moon has an orbital period of 31.6 hours. Based on mutual eclipse/occultation events, the satellite is thought to be at least 29% the size of Seilandfarm, which translates into a diameter of approximately 2 kilometers or more.

2121 Sevastopol, provisional designation , is a stony Florian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 27 June 1971, by Russian astronomer Tamara Smirnova at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula. Its minor-planet moon was discovered in 2010.

The constellations Phoenix, Grus, Pavo and Tucana, are known as the Southern Birds. The brightest star, Alpha Phoenicis, is named Ankaa, an Arabic word meaning 'the Phoenix'. It is an orange giant of apparent magnitude 2.4. Next is Beta Phoenicis, actually a binary system composed of two yellow giants with a combined apparent magnitude of 3.3.

The Bibi-binary system for numeric notation (in French système Bibi-binaire, or abbreviated "système Bibi") is a hexadecimal numeral system first described in 1968Brevet d'invention n° 1.569.028, Procédé de codification de l'information, Robert Jean Lapointe, demandé le 28 mars 1968, délivré le 21 avril 1969. Downloaded from INPI. by singer/mathematician Robert "Boby" Lapointe (1922–1972).

During the photometric observations in March 2012, Brian Warner found evidence of the existence of a minor-planet moon orbiting McAuliffe every 20.86 hours. However, it is only a "possible" synchronous binary system, as no mutual eclipsing/occultation events were observed. Follow-up observations in September and October 2016, did not confirm the binary nature of McAuliffe.

702 Alauda , provisional designation , is a carbonaceous asteroid and binary system from the outer asteroid belt, approximately 190 kilometers in diameter. It is the parent body of the Alauda family. Discovered in 1910 by German astronomer Joseph Helffrich at Heidelberg Observatory, it was named after the lark (alauda). Its small moon, named Pichi üñëm, was discovered in 2007.

This method is used solely for binary systems. The mass of the binary system is assumed to be twice that of the Sun. Kepler's Laws are then applied and the separation between the stars is determined. Once this distance is found, the distance away can be found via the arc subtended in the sky, providing a temporary distance measurement.

' is a sub-kilometer asteroid and binary system, classified as near-Earth object of Apollo group discovered by NEAT at Palomar Observatory on 18 September 2001. It measures approximately 960 meters in diameter, while its 2001-discovered minor-planet moon has an estimated diameter of 200 meters based on a secondary to primary mean-diameter ration of 0.28.

Using a ternary code in the alphabet would have resulted in shorter messages because fewer elements are required in each codepoint, but a binary system is easier to read at long distance since fewer flag positions need to be distinguished. Myer's manual also describes a ternary-coded alphabet with a fixed length of three elements for each codepoint.

An infrared excess has been detected around this system, most likely indicating the presence of a circumstellar disk at a radius of 34.2 AU. The temperature of this dust is 40 K. The estimated mass of the dust is 0.0002 times the mass of the Earth. It is aligned to within 10° of the plane of the binary system.

In 1951 Sarah L. Lippincott made the first reasonably accurate predictions of the position of the secondary star using the refractor telescope of the Sproul Observatory. These calculations were used by Walter Baade to find and optically resolve this binary system for the first time using the then new Hale Telescope at the Palomar Observatory in California.

The variable radial velocity of this system was announced in 1922 by W. W. Campbell. It is a single-lined spectroscopic binary system with an orbital period of and an eccentricity of 0.38. The value is , where a is the semimajor axis and i is the orbital inclination. This provides a lower bound on the true semimajor axis.

It was a spinning satellite with pointing capability. SAS 3 was the first to discover X-rays from a highly magnetic WD binary system, AM Her, discovered X-rays from Algol and HZ 43, and surveyed the soft X-ray background (0.1-0.28 kev). Tenma was the second Japanese X-ray astronomy satellite launched on Feb 20 1983.

Theta Eridani is a binary system with some evidence suggesting it is part of a multiple star system.NSV 01002, database entry, New Catalogue of Suspected Variable Stars, the improved version, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line February 26, 2010. The main star, θ¹ Eridani, is of spectral class A4 with a +3.2 apparent magnitude.

WR 114 is listed in the Catalogue of galactic Wolf Rayet stars as a possible binary system with an OB companion, but more recent studies have not confirmed this and it is now considered a single WC5 star. No x-rays have been detected from WR 114, which would be expected by a close hot companion.

The Okayama Planet Search team published a paper in late 2008 reporting investigations into radial velocity variations observed for a set of evolved stars, showing hints of a substellar companion orbiting the primary member of the wide binary system 27 Hydrae. Its orbital period is estimated at 9.3 years, but no planet has been confirmed yet.

113 Amalthea is a stony Florian asteroid and binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 12 March 1871, by German astronomer Robert Luther at the Bilk Observatory in Düsseldorf, Germany. The elongated S-type asteroid has a rotation period of 9.95 hours. It was named after Amalthea from Greek mythology.

The AM Herculis binary system contains a white dwarf and a red dwarf. The white dwarf is accreting material directly from the red dwarf without an accretion disk. The white dwarf primary is highly magnetic and the infalling material is channelled towards the magnetic poles. The accretion rate is unstable, at times decreasing dramatically and reducing the brightness of the whole system.

The brighter component is an A-type main-sequence star with a stellar classification of A0Va. It may form a binary system of two roughly equal stars. An infrared excess suggests there is a debris disk orbiting from the star with a mean temperature of 95 K. It has one visual companion at an angular separation of about and magnitude 13.7.

Gliese 570 (or 33 G. Librae) is a quaternary star system approximately 19 light-years away. The primary star is an orange dwarf star (much dimmer and smaller than the Sun). The other secondary stars are themselves a binary system, two red dwarfs that orbit the primary star. A brown dwarf has been confirmed to be orbiting in the system.

41 Daphne has at least one satellite, named Peneius (provisionally S/2008 (41) 1). It was identified on March 28, 2008, and has a projected separation of 443 km, an orbital period of approximately 1.1 days, and an estimated diameter of less than 2 km. If these preliminary observations hold up, this binary system has the most extreme size ratio known.

PSR J0348+0432 is a pulsar-white dwarf binary system. It was discovered in 2007 with the National Radio Astronomy Observatory, Green Bank's Robert C. Byrd Green Bank Telescope in a drift-scan survey. In 2013, a mass measurement for this neutron star was announced: . This measurement was done with a combination of radio timing and precise spectroscopy of the white dwarf companion.

Rho3 Arietis (Rho3 Ari, ρ3 Arietis, ρ3 Ari) is the Bayer designation for a star in the northern constellation of Aries. It is faintly visible to the naked eye with an apparent visual magnitude of 5.63. Based upon an annual parallax shift of 28.29 mas, this star is located at a distance of approximately from Earth. This is an astrometric binary system.

DV Aquarii is a binary star system in the zodiac constellation of Aquarius. It has a peak apparent visual magnitude of 5.89, which is bright enough to be visible to the naked eye. The distance can be estimated from its annual parallax shift of , yielding a separation of 291 light years. This is a detached eclipsing binary system of the Beta Lyrae type.

3854 George, provisional designation ', is a stony Hungaria asteroid and Mars- crosser from the innermost regions of the asteroid belt, approximately in diameter. It was discovered on 13 March 1983, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California. The unlikely synchronous binary system has a rotation period of 3.3 hours. It was named after the discoverer's father-in-law, .

2873 Binzel, provisional designation , is a stony Florian asteroid and binary system from the inner regions of the asteroid belt, approximately 6.5 kilometers in diameter. It was discovered on 28 March 1982, by American astronomer Edward Bowell at the Anderson Mesa Station in Flagstaff, Arizona. The asteroid was named after astronomer Richard Binzel. Its 1.6-kilometer minor-planet moon was discovered in 2019.

1830 Pogson, provisional designation , is a stony Florian asteroid and an asynchronous binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 17 April 1968, by Swiss astronomer Paul Wild at the Zimmerwald Observatory near Bern, Switzerland. The S-type asteroid has a rotation period 2.6 of hours. It was named for English astronomer Norman Pogson.

The total brightness change is only 0.15 magnitudes. The third component is a B0.5 main sequence star in a long eccentric orbit around the close pair. It is fainter and cooler than either of the two close stars, yet it is calculated to be more massive than δ Cir A, so it is suspected that it may also be a close binary system.

It is drifting further away with a radial velocity of +17 km/s. The variable velocity of this system was first noted during a study at Mount Wilson observatory in 1952. It is a double-lined spectroscopic binary system with an orbital period of and an eccentricity of 0.24. Both components are similar, aging giant stars, a relatively rare combination.

1355 Magoeba, provisional designation , is a Hungaria asteroid and a suspected binary system from the innermost regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 30 April 1935, by English-born, South African astronomer Cyril Jackson at the Johannesburg Observatory in South Africa. The asteroid is named for Magoeba, a tribal chief in the South African Transvaal Province.

' is a resonant trans-Neptunian object and binary system from the Kuiper belt in the outermost regions of the Solar System. It was discovered on 16 September 1998, by American astronomer Nichole Danzl at the Kitt Peak National Observatory in Arizona. It is classified as a twotino and measures approximately 280 kilometers in diameter. Its minor-planet moon was discovered in 2001.

Omicron Puppis (ο Puppis) is candidate binary star system in the southern constellation of Puppis. It is visible to the naked eye, having a combined apparent visual magnitude of +4.48. Based upon an annual parallax shift of 2.30 mas as seen from Earth, it is located roughly 1,400 light years from the Sun. This is a suspected close spectroscopic binary system.

This is a spectroscopic binary system with an orbital period of 0.6 days. The combined spectrum matches a stellar classification of B1npe. The 'e' suffix indicates that this is a Be star with emission lines in the spectrum. An 'n' means that the absorption lines in the spectrum are broadened from the Doppler effect as a result of rapid rotation.

The variable radial velocity of the brighter component was first observed by H. A. Abt in 1961. It is a double-lined spectroscopic binary system with an orbital period of 27.2 days and an eccentricity of 0.74. They have a combined magnitude of 4.71. Both components are similar stars with a combined stellar classification of kA2hA5VmA5, and one or both are Am stars.

However, the "binary hypothesis" posits that binary stars are more likely to produce non-spherical nebulae. For LoTr 5, the binary system likely played a role in shaping the nebula. A modelling of LoTr 5 shows that it is composed of two round lobes, making a peanut shape. The semimajor and semiminor axes are about 390 arcsec and 100 arcsec, respectively.

The x-ray source at the core of NGC 300 is designated NGC 300 X-1. Astronomers speculate that NGC 300 X-1 is a new kind of Wolf-Rayet black hole binary system similar to the confirmed such system IC 10 X-1. Their shared properties include an orbital period of ~30 hours and x-ray brightness of ~1 ergs.

Contemporary Monacans, University of Virginia , accessed 6 May 2008Monacan Indian Nation , accessed 6 May 2008 Over time, Native Americans in Virginia intermarried with Europeans and African Americans. Whites assumed that meant that they no longer identified as Indians, but were mistaken. In 1924, Virginia passed a Racial Integrity Act, which instituted a binary system of racial classification as black or white only.

Polytechnics Polytechnics were tertiary education teaching institutions in England, Wales and Northern Ireland. The comparable institutions in Scotland were collectively referred to as Central Institutions. From 1965 to 1992, UK polytechnics operated under the binary system of education along with universities. Polytechnics offered diplomas and degrees (bachelor's, master's, PhD) validated at the national level by the Council for National Academic Awards (CNAA).

The system is moving away from the Sun with a radial velocity of +30 km/s. Epsilon Cancri A is a double-lined spectroscopic binary system with an orbital period of 35 days and eccentricity of 0.32. It has a stellar classification of A5 III, which matches an A-type giant star. The spectrum displays the chemically peculiar characteristics of an Am star.

DT Virginis, also known as Ross 458 AB, is a binary star in the constellation of Virgo. Both of the stars are low-mass red dwarfs with at least one of them being a flare star. This binary system has a circumbinary planet detected by direct imaging, currently the planetary-mass object with the widest known orbit around a binary star.

Theta Cephei, Latinized from θ Cephei, is a stellar class A7, fourth-magnitude star in the constellation Cepheus. It is a white-hued, single-lined spectroscopic binary system, located about 127 light-years from Earth. The pair have an orbital period of 840.6 days with a low eccentricity of 0.03. Shared with η Cep, this star system has the title Al Kidr.

WASP-8 is a magnitude 9.9 main-sequence yellow dwarf star. It is reported to be a G-type star of temperature 5600 K, mass of 0.93 solar masses, radius of 0.93 solar radius, and a luminosity of 0.79 of solar luminosity. There is a companion star located 4 arcseconds away with the same proper motion indicating a stellar binary system.

The asteroid is characterized as both a carbonaceous C-type and metallic M-type asteroid. The density of the primary was calculated using the orbital elements of the binary system, the primary- to-secondary mass ratio, and estimates of the primary size. The primary has a low density of 1.7 g/cm3, which may indicate a "rubble pile" structure containing rocks and voids.

During Pravec's photometric observations it was revealed that Adriángalád is a synchronous binary system, with a minor-planet moon orbiting it every hours. It received the provisional designation . The satellite measures approximately 40% of that of its primary, with published diameters of 1.62 and 1.69 kilometers, respectively. The companion orbits its primary at an estimated average distance of 13 kilometers only.

Ultraviolet rays emitted from WR 136's hot surface cause the shell to glow. There is some evidence WR 136 may be a binary star. Its companion would be a low-mass star of spectral classification K or M that would complete an orbit around the Wolf-Rayet star each 5.13 days, being the progenitor of a low-mass X-ray binary system.

Binary systems of sub-brown dwarfs are theoretically possible; Oph 162225-240515 was initially thought to be a binary system of a brown dwarf of 14 Jupiter masses and a sub-brown dwarf of 7 Jupiter masses, but further observations revised the estimated masses upwards to greater than 13 Jupiter masses, making them brown dwarfs according to the IAU working definitions.

Xi Cephei A is a double-lined spectroscopic binary system with an orbital period of 810.9 days and an eccentricity of 0.46. The primary, component Aa, is a chemically peculiar Am star, a probable subgiant with an apparent magnitude of +4.29. Eight arcseconds away, Xi Cephei B is another spectroscopic binary. Xi Cephei C is a 13th magnitude star nearly two arcminutes away.

In Sandoval, Jonathan (Ed.) Handbook of crisis counseling, intervention, and prevention in the schools, pp. 301 ff. Psychology Press, Acknowledging their lesbian, gay or bisexual identity, or other identity, can bring an end to confusion. With regard to gender identity, terms for those who do not comply to the gender binary system are, for example, genderqueer, agender, or gender neutral.

The masses of stars are difficult to measure except by determination of a binary orbit. Eta Carinae is a binary system, but certain key information about the orbit is not known accurately. The mass can be strongly constrained to be greater than , due to the high luminosity. Standard models of the system assume masses of and for the primary and secondary respectively.

It was unclear whether the pair formed a visual double or a binary system. The authors of the study estimated a class of K2 V, based upon a visual magnitude difference of . Subsequent observations using adaptive options did not spot this companion and it was concluded this was a false detection. However, a low mass stellar companion was detected in a wide orbit.

This is a single-lined spectroscopic binary system with an orbital period of 363.57 days and an eccentricity of 0.35. The pair were resolved through speckle interferometry in 1977, showing an angular separation of . They were later resolved in 1981 with a separation of , but were unresolved during 20 other attempts between 1976–1991. The system is a source of X-ray emission.

These three stars are referred to as Aa, Ab1, and Ab2, not to be confused with the fainter visible star 0.15 arc-seconds distant. UW Canis Majoris is another 4th magnitude star less than half a degree away, and is itself an eclipsing binary system associated with NGC 2362. It has been catalogued as τ2 CMa, but that name is now rarely used.

An early project for the U.S. Air Force, BINAC attempted to make a lightweight, simple computer by using binary arithmetic. It deeply impressed the industry. As late as 1970, major computer languages were unable to standardize their numeric behavior because decimal computers had groups of users too large to alienate. Even when designers used a binary system, they still had many odd ideas.

The star is radiating 24 times the Sun's luminosity from its photosphere at an effective temperature of 7,476 K. It has a relatively low projected rotational velocity of under 20 km/s, and it is suspected the rotations of this binary system may be synchronized. The system is a source for X-ray emission, which is most likely coming from the secondary.

The planet would be ejected unless its periastron distance was increased away from the binary, such as by a gravitational encounter with a passing star during apastron. An analysis of the motions of 461 nearby stars using Gaia observations revealed two (HIP 59716 and HIP 59721, a possible loosely bound binary system) that passed within of between 2 and 3 million years ago.

Each of the members of a close binary system raises tides on the other through gravitational interaction. However the bulges can be slightly misaligned with respect to the direction of gravitational attraction. Thus the force of gravity produces a torque component on the bulge, resulting in the transfer of angular momentum (tidal acceleration). This causes the system to steadily evolve, although it can approach a stable equilibrium.

This is a probable astrometric binary system with the components having an angular separation of 7.2 arcseconds along a position angle of 241°, as of 2014. The primary is an evolved G-type giant star with a stellar classification of G9 III. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified.

The primary asteroid was discovered in 1996 by Joe Montani of the Spacewatch Project at the University of Arizona. The name Didymos was officially approved in 2004. Petr Pravec of the Ondřejov Observatory in the Czech Republic found in 2003 that the asteroid had a satellite orbiting it. With his collaborators, he confirmed from the Arecibo radar delay-Doppler images that Didymos is a binary system.

Juan Caramuel y Lobkowitz worked extensively on logarithms including logarithms with base 2. Thomas Harriot's manuscripts contained a table of binary numbers and their notation, which demonstrated that any number could be written on a base 2 system. Regardless, Leibniz simplified the binary system and articulated logical properties such as conjunction, disjunction, negation, identity, inclusion, and the empty set. He anticipated Lagrangian interpolation and algorithmic information theory.

It ranges from magnitude 9.8 to 11.2 over an optical period of 160 days. It is 770 ± 40 light-years distant from the Sun. TT Crateris is a cataclysmic variable; a binary system composed of a white dwarf around as massive as the Sun in close orbit with an orange dwarf of spectral type K5V. The two orbit each other every 6 hours 26 minutes.

The stars are oval-shaped as they are gravitationally distorted by each other. TV Pictoris is a spectroscopic binary system composed of an A-type star and an F-type star which rotate around each other in a very close orbit. The latter star is elliptical in shape and itself varies in brightness. The visual magnitude ranges between 7.37 and 7.53 every 20 hours.

The binary system has an orbital period of 2 days, 5 hours, and 56 minutes. The two stars are separated by only 15 times the width of the sun, or less than twice their own diameters. The more massive primary orbits at 200 km/s, while the secondary moves at 350 km/s, and the system as a whole is approaching us at around 300 km/s.

5905 Johnson, provisional designation , is a Hungaria asteroid and synchronous binary system from the innermost regions of the asteroid belt, approximately in diameter. It was discovered on 11 February 1989, by American astronomer Eleanor Helin at Palomar Observatory in California, United States. Its satellite measures approximately in diameter and orbits its primary every 21.8 hours. It was named after American astronomer and engineer Lindley N. Johnson.

16974 Iphthime (; prov. designation: ) is a Jupiter trojan and a binary system from the Greek camp, approximately in diameter. It was discovered on 18 November 1998, by astronomers with the Lincoln Near-Earth Asteroid Research at the ETS Test Site in Socorro, New Mexico. The dark Jovian asteroid belongs to the 80 largest Jupiter trojans and has a notably slow rotation of 78.9 hours.

4435 Holt, provisional designation ', is a stony asteroid, sizable Mars- crosser and binary system from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 13 January 1983, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California, United States. It was later named after American astronomer Henry E. Holt. The discovery of its companion was announced in January 2018.

1338 Duponta, provisional designation , is a stony Florian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 7.8 kilometers in diameter. It was discovered on 4 December 1934, by French astronomer Louis Boyer at the Algiers Observatory in Algeria, North Africa. It was named after the discoverer's nephew, Marc Dupont. The asteroid's unnamed minor-planet moon was discovered in March 2007.

3800 Karayusuf, provisional designation ', is a Mars-crossing asteroid and suspected binary system from inside the asteroid belt, approximately in diameter. It was discovered on 4 January 1984, by American astronomer Eleanor Helin at the Palomar Observatory in California. The S/L-type asteroid has a short rotation period of 2.2 hours. It was named after Syrian physician Alford Karayusuf, a friend of the discoverer.

17246 Christophedumas, provisional designation , is a stony Koronian asteroid and binary system from the outer regions of the asteroid belt, approximately 4.6 kilometers in diameter. It was discovered on 5 April 2000, by the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, United States. It was named after planetary scientist Christophe Dumas. The asteroid's minor-planet moon was discovered in 2004.

A more recent hypothesis suggests that, before its capture, Triton was part of a binary system. When this binary encountered Neptune, it interacted in such a way that the binary dissociated, with one portion of the binary expelled, and the other, Triton, becoming bound to Neptune. This event is more likely for more massive companions. Similar mechanisms have been proposed for the capture of Mars's moons.

1798 Watts, provisional designation , is a stony asteroid and binary system from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 4 April 1949, by IU's Indiana Asteroid Program at Goethe Link Observatory near Brooklyn, Indiana, United States. The asteroid was named for American astronomer Chester Burleigh Watts. Its small minor- planet moon has a period of 26.96 hours.

' is an eccentric, stony asteroid and binary system, classified as near-Earth object of the Amor group of asteroids, approximately 900 meters in diameter. It minor-planet moon, S/2001 (31345) 1', has an estimated diameter of 270 meters. This asteroid was discovered on 3 August 1998, by the Lowell Observatory Near-Earth-Object Search (LONEOS) at Anderson Mesa Station, near Flagstaff, Arizona, United States.

Chini et al. (2012) identified this as a single-lined spectroscopic binary system. The visible component is a B-type main-sequence star with a stellar classification of B8 V. It is about 17 million tears old and is spinning rapidly with a projected rotational velocity of 251 km/s. The star has 3.6 times the mass of the Sun and 3.05 times the Sun's radius.

Orcus and Vanth are known to constitute a binary system. The mass of the system has been estimated to be , approximately equal to that of the Saturnian moon Tethys (). Compared to the most massive known dwarf planet, , the mass of the Orcus system is about 3.8 percent that of Eris (). How this mass is partitioned between Orcus and Vanth depends on their relative densities.

This is listed as an eclipsing binary system with a period of 47.9 days and has the variable star designation RR Arietis. During each eclipse of the primary star, the magnitude of the system decreases by 0.40. The eclipse of the secondary reduces the magnitude by 0.35. The primary component of the system is an evolved giant star with a stellar classification of K1 III.

10208 Germanicus, provisional designation , is a stony Florian asteroid and binary system from the inner regions of the asteroid belt, approximately 3.5 kilometers in diameter. It was discovered on 30 August 1997, by Italian amateur astronomer Antonio Vagnozzi at the Santa Lucia Stroncone Astronomical Observatory in Stroncone, Italy, and named for ancient Roman general Germanicus. The asteroid's minor-planet moon was discovered in 2007.

PSR J0737−3039 is the only known double pulsar. It consists of two neutron stars emitting electromagnetic waves in the radio wavelength in a relativistic binary system. The two pulsars are known as PSR J0737−3039A and PSR J0737−3039B. It was discovered in 2003 at Australia's Parkes Observatory by an international team led by the radio astronomer Marta Burgay during a high- latitude pulsar survey.

A Bancroft point is the temperature where an azeotrope occurs in a binary system. Although vapor liquid azeotropy is impossible for binary systems which are rigorously described by Raoult's law, for real systems, azeotropy is inevitable at temperatures where the saturation vapor pressure of the components are equal. Such a temperature is called a Bancroft point. However, not all azeotropic binary systems exhibit such a point.

There has also been reported an observation of a bright, rapidly rotating giant star in a binary system with an unseen companion emitting no light, including x-rays, but having a mass of solar masses. This is interpreted to suggest that there may be many such low-mass black holes that are not currently consuming any material and are hence undetectable via the usual x-ray signature.

Simulated animation of the Moshup binary system In 2019, Perkin Observatory was noted for pointing out the flyby of the Near-Earth asteroid 1999 KW4 (66391 Moshup) by a local radio station. They recommend viewing it with at least a 8-inch aperture telescope, and that it would be about 3 million miles away from the Earth during its flyby. The asteroid will not return until 2036.

1016 Anitra, provisional designation , is a stony Florian asteroid and suspected asynchronous binary system from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 31 January 1924, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The asteroid was likely named after the fictional character Anitra from Henrik Ibsen's drama Peer Gynt.

TU Corvi is a yellow-white hued star in the southern constellation of Corvus. It is a dimly visible to the naked eye with an apparent visual magnitude of 6.20. The distance to this star can be estimated from its annual parallax shift of , yielding a range of about 240 light years. Based upon measured changes in its proper motion, it may be a close binary system.

2047 Smetana, provisional designation , is a bright Hungaria asteroid and synchronous binary system from the innermost regions of the asteroid belt, approximately 3.5 kilometers in diameter. It was discovered on 26 October 1971, by Czech astronomer Luboš Kohoutek at Bergedorf Observatory in Hamburg, Germany. The asteroid was named after Czech composer Bedřich Smetana. Its sub- kilometer sized minor-planet moon was discovered in 2012.

4383 Suruga, provisional designation , is a Vestian asteroid and binary system from the inner regions of the asteroid belt, approximately 6.5 kilometers in diameter. It was discovered on 1 December 1989, by Japanese astronomer Yoshiaki Oshima at Gekko Observatory, Japan. The asteroid was named after the former Japanese Suruga Province. Its synchronous minor-planet moon, , measures approximately 1.33 kilometers and has a period of 16.386 hours.

13123 Tyson, provisional designation , is a stony Phocaea asteroid and an asynchronous binary system from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on May 16, 1994, by American astronomer Carolyn Shoemaker and Canadian astronomer David Levy at the Palomar Observatory in California, United States. The asteroid was named for Neil deGrasse Tyson, American astrophysicist and popular science communicator.

'469705 ǂKá̦gára, official designation ', is a trans-Neptunian object and binary system of the core Kuiper belt, located in the outermost region of the Solar System. It was discovered on 2005 March 11 by Marc William Buie at Kitt Peak Observatory. The primary body measures perhaps in diameter. Its ≈120-kilometer (75-mile) companion ǃHãunu was discovered with the Hubble Space Telescope in 2009.

About 25 stars are visible in a telescope with a aperture. M26 spans a linear size of 22 light years across with a tidal radius of , and is at a distance of 5,160 light years from the Earth. The brightest star is of magnitude 11 and the age of this cluster has been calculated to be 85.3 million years. It includes one known spectroscopic binary system.

This is a probable astrometric binary system. The primary, component A, is an evolved giant star with a stellar classification of K0 III. It is a red clump star that is generating energy through the fusion of helium at its core. The measured angular diameter is , which, at the estimated distance of Psi Hydrae, yields a physical size of about 10.6 times the radius of the Sun.

She was the first to use tomography in astronomy. At first, it was widely used in medicine or archeology, but Richards found the utility of this to test the gas-flow model that she created for her doctoral thesis. She used tomography to observe the binary system as it moves in relation to the Earth. This proves how the gas flows between the stars.

' is a bright sub-kilometer asteroid and binary system, classified as near- Earth object and potentially hazardous asteroid of the Apollo group, approximately in diameter. It was discovered on 30 January 2004 by astronomers of the Lincoln Near-Earth Asteroid Research at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico. Its moon was discovered during the asteroid's close approach to the Earth in January 2015.

R Coronae Australis (R CrA) is a variable binary system in the constellation Corona Australis. It has varied between magnitudes 10 and 14.36. A small reflection/emission nebula NGC 6729 extends from the star towards SE. This star is moving toward the Solar System with a radial velocity of . It was previously believed that in roughly 222,000 years, this system could have approached within of the Sun.

The primary star is probably undergoing wind roche lobe overflow (WRLOF) with a portion of the material being transferred to the secondary. This is a possible evolutionary path to a stripped-envelope Wolf-Rayet binary system. The interaction between the pair should spin up the primary to synchronous rotation, which is a possible path to fast-spinning luminous blue variables or B[e] stars.

', provisional designation , is a background asteroid and binary system from the inner regions of the asteroid belt. It was discovered on 11 October 1985, by astronomer by T. F. Fric and Richard Gilbrech at the Palomar Observatory in California. It is the only minor-planet discovery for these two astronomers. The stony L-type asteroid measures approximately in diameter and has a rotation period of 2.7 hours.

SuWt 2 is a planetary nebula viewed almost edge-on in the constellation of Centaurus. It is believed that high UV radiations from an undiscovered white dwarf ionizes this nebula. Currently, there is a binary system consisting of two A-type main-sequence stars whose radiations are not enough to photo-ionize the surrounding nebula. The nebula is easily obscured by the brighter star, HD 121228.

20325 Julianoey, provisional designation , is a Vestian asteroid and a synchronous binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 21 April 1998, by astronomers of the Spacewatch survey at Kitt Peak National Observatory near Tucson, Arizona. The asteroid was named after Australian photometrist Julian Oey. The discovery of its minor-planet moon was announced in December 2014.

The recurrent nova is produced by a white dwarf star and a red giant in a binary system. About every 20 years, enough material from the red giant builds up on the surface of the white dwarf to produce a thermonuclear explosion. The white dwarf orbits close to the red giant, with an accretion disc concentrating the overflowing atmosphere of the red giant onto the white dwarf.

Epsilon Tucanae traditionally marks the toucan's left leg. A B-type subgiant, it has a spectral type B9IV and an apparent magnitude of 4.49. It is approximately 373 light-years from Earth. It is around four times as massive as our Sun. Theta Tucanae is a white A-type star around 423 light- years distant from Earth, which is actually a close binary system.

It is classified as B7 main sequence star with a mass of . The cluster contains another dozen or so 9th and 10th magnitude stars and many fainter stars. S Monocerotis A is a spectroscopic binary system with an orbital period of 74 years. Since 1943, the spectrum of this star has served as the MK standard for O7 by which other stars are classified.

Tau9 Eridani (τ9 Eri) is a binary star in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 4.63. The distance to this system can be estimated using the parallax method, which yields a value of roughly 327 light years. This is a single-lined spectroscopic binary system with an orbital period of 5.9537 days and an eccentricity of 0.1.

This is a single-lined spectroscopic binary system. The ROSAT All Sky Survey discovered that Alpha Sagittarii is emitting an excess flux of X-rays, which is not expected to originate from a star of this spectral class. The most likely explanation is that the companion is an active pre-main sequence star or else a star that has just reached the main sequence.

Measurement of the stars proper motion over time suggest changes due to an acceleration component, which may indicate it is a close binary system. The visible component has a stellar classification of G5 V, indicating it is an ordinary G-type main-sequence star that is generating energy through hydrogen fusion in its core region. Hall et al. (2007) classify it as a low-activity variable star.

The double-lined nature of this spectroscopic binary system was not announced until 1972. It has an orbital period of and an eccentricity of 0.551. Both components appear to be slightly evolved stars that are leaving the main sequence and becoming subgiant stars, with stellar classifications of F8IV-V and F9IV-V. They each have slightly greater mass than the Sun: 107% and 105%, respectively.

Omega Eridani (ω Eri) is a binary star system in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude is 4.37. The distance to this star, as determined by the parallax method, is around 235 light years. This is a single-lined spectroscopic binary system with an orbital period of 3,057 days (8.4 years) and an eccentricity of 0.46.

NSVS 14256825, also known as V1828 Aquilae, is an eclipsing binary system (of the Algol type) in the constellation of Aquila. The system comprises an eclipsing subdwarf OB star and red dwarf star. The two stars orbit each other every 2.648976 hours. Based on the stellar parallax of the system, observed by Gaia, the system is located approximately 2,700 light-years (840 parsecs) away.

The brightest component is a white A-type subgiant. It is a member of a spectroscopic binary system whose components have an orbital period of 4,028 days. The companion, which has not been directly observed, is thought to be a white dwarf with a mass of . The companion binary is composed of the 9th magnitude and 10th magnitude stars, both of which are red dwarfs.

', provisional designation , is a trans-Neptunian object and binary system from the classical Kuiper belt, located in the outermost region of the Solar System. The cubewano belongs to the cold population and measures approximately . It was first observed on 10 December 2001, by astronomers at the Mauna Kea Observatory, Hawaii. Its 140-kilometer sized companion was discovered by the Hubble Space Telescope in June 2006.

Images taken several days earlier revealed no such star, indicating destruction of the star occurred on the 22 September. The progenitor of SN 2004et has been identified on earlier images –– only the seventh time that such an event was directly identified with its host star. The red supergiant progenitor had an initial mass of about 15 in an interacting binary system shared with a blue supergiant.

It has also been catalogued as a member of the Hyades group. However, Griffin (2005) suggests it belongs to neither. This is a single-lined spectroscopic binary system with an orbital period of 81.5 days and a significant eccentricity of 0.14. It has an value of , where a is the semimajor axis and i is the orbital inclination to the line of sight from the Earth.

A simplification for many binary addition problems is the Long Carry Method or Brookhouse Method of Binary Addition. This method is generally useful in any binary addition in which one of the numbers contains a long "string" of ones. It is based on the simple premise that under the binary system, when given a "string" of digits composed entirely of ones (where: is any integer length), adding 1 will result in the number 1 followed by a string of zeros. That concept follows, logically, just as in the decimal system, where adding 1 to a string of 9s will result in the number 1 followed by a string of 0s: Binary Decimal 1 1 1 1 1 likewise 9 9 9 9 9 \+ 1 + 1 ——————————— ——————————— 1 0 0 0 0 0 1 0 0 0 0 0 Such long strings are quite common in the binary system.

R145 is a double-lined spectroscopic binary system with an orbital period of 159 days. The two stars have an eccentric orbit with a separation varying from less than one AU to nearly eight AU. They have almost identical orbital velocities and hence very similar masses. The exact values depend on the inclination of the orbital plane. The inclination of the R145 orbit calculated using polarimetry is 39°.

Beta² Sagittarii (β² Sagittarii, abbreviated Beta² Sgr, β² Sgr) is a star in the zodiac constellation of Sagittarius. It is visible to the naked eye, having an apparent visual magnitude of +4.29. Based upon an annual parallax shift of 24.31 mas as seen from Earth, it is located 134 light-years from the Sun. Based upon variations in its proper motion, this is a probable astrometric binary system.

The value is believed to be accurate to about 2%, but there are some discrepancies in the orbital fit. 30 Cygni is another naked eye star a tenth of a degree away, forming a bright triple. 32 Cygni is about a degree away to the north, also a detached eclipsing binary system. It comprises a large cool evolved star and a small hot main sequence or subgiant companion.

42 Orionis, also called c Ori, is a B1V magnitude star in the northern half of the Orion nebula. Theta Orionis has a more central position in the nebula, and is actually composed of a multi-star system. Iota Orionis is one of the brightest in the collection, in the south of the Orion nebula. Iota Orionis is a spectroscopic binary system, with a variable magnitude of O9III.

WR 137 has a spectrum with CIII emission weaker than CIV and OV weaker still, leading to the assignment of a WC7 spectral type. The spectrum also shows emission lines of HeII and OIV. WR 137 is a binary system, with an O9 main sequence or giant companion. The two stars orbit every thirteen years in a mildly eccentric orbit, and there is an episode of dust production near periastron.

All his creations, however, are the > result of a labour-intensive process. A process in which rules apply that > the artist has set himself, conditions the works must eventually meet. He > follows a binary system, by which a space is there or it isn’t, it is filled > in, or it is open. Within the limits of his own rules he explores possible > variations by means of this system.

X Persei is a binary system containing a γ Cassiopeiae variable and a pulsar. It has a relatively long period and low eccentricity for this type of binary, which means the x-ray emission is persistent and not usually strongly variable. Some strong x-ray flares have been observed, presumably related to changes in the accretion disc, but no correlations have been found with the strong optical variations.

3841 Dicicco, provisional designation , is a stony Florian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 4 November 1983, by American astronomer Brian Skiff at Lowell's Anderson Mesa Station near Flagstaff, Arizona, in the United States. It was named after American astronomer Dennis di Cicco. Its minor-planet moon, provisionally designated , was discovered in 2014.

7958 Leakey, provisional designation , is a Hungaria asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 3 kilometers in diameter. It was discovered on 5 June 1994, by American astronomer-couple Carolyn and Eugene Shoemaker at the Palomar Observatory in California, United States. Its minor-planet moon was discovered in 2012. The asteroid was named after the members of the Leakey family: Mary, Louis and Richard.

In 1901, κ Pavonis was reported to be a variable star with a magnitude range of 3.8 to 5.2 with a period of 9.0908 days. Further observations revealed radial velocity variations in time with the brightness variations, but this was assumed to indicate a spectroscopic binary system. The brightness variations were then interpreted as eclipses. Less than 10 years later, was κ Pav was listed as a likely Cepheid variable.

This is a single-lined spectroscopic binary system with an orbital period of just 1.71 days in a circular orbit. The unresolved components are close enough that their tidal interaction is significant. The visible component is a slowly pulsating B-type star with a stellar classification of B7III. This implies it is an evolved giant star, but it is actually more likely to be on the main sequence.

Lambda Pyxidis (λ Pyxidis) is a yellow-hued star in the southern constellation of Pyxis. It is visible to the naked eye, having an apparent visual magnitude of 4.68. Based upon an annual parallax shift of 16.98 mas as seen from Earth, it is located around 192 light years from the Sun. Measurements of changes in the star's proper motion over time indicate this is an astrometric binary system.

Delta Delphini, Latinized from δ Delphini, is a binary star in the northern constellation of Delphinus. It is visible to the naked eye with an apparent visual magnitude of 4.43. Based upon an annual parallax shift of 14.61 mas as seen from the Earth, the system is located about 223 light years from the Sun. This is a double-lined spectroscopic binary system with an orbital period of 40.58 days.

BI 253 is one of the hottest, most massive, and most luminous known main sequence stars. The temperature is around 50,000 K, the luminosity over , and the mass over , although it is less than . The rotation rate of at least 200 km/s is high, but this is common in the youngest and hottest stars, either due to spin-up during stellar formation or merger of a close binary system.

The binary system lies 11,000 parsecs away in Aquila. GRS 1915+105 is the heaviest of the stellar black holes so far known in the Milky Way Galaxy, with 10 to 18 times the mass of the Sun. It is also a microquasar, and it appears that the black hole rotates at close to 1,150 times per second, with a spin parameter value between 0.82 and 1.00 (maximum possible value).

', provisional designation , is a dark asteroid and synchronous binary system, classified as near-Earth object and potentially hazardous asteroid of the Amor group, approximately 3 kilometers in diameter. It was discovered on 19 August 1998, by astronomers of the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. Its sub-kilometer minor-planet moon was discovered by radar on 30 May 2013.

Two possible scenarios were proposed to explain the composition of extreme helium stars. # The double-degenerate (DD) model explained the stars as forming in a binary system consisting of a smaller helium white dwarf and a more massive carbon-oxygen white dwarf. Both stars had ceased to produce energy through nuclear fusion and were now compact objects. The emission of gravitational radiation caused their orbit to decay until they merged.

4440 Tchantchès, provisional designation , is a rather elongated Hungaria asteroid and a possible binary system from the inner regions of the asteroid belt, approximately 3 kilometers in diameter. It was discovered on 23 December 1984, by astronomer François Dossin at Haute-Provence Observatory in France and named after the Belgian folklore character Tchantchès. It is possibly orbited by a sub-kilometer sized minor-planet moon every 15 hours.

II Pegasi is a binary star system in the constellation of Pegasus with an apparent magnitude of 7.4 and a distance of 130 light years. It is a very active RS Canum Venaticorum variable (RS CVn), a close binary system with active starspots. The primary (II Pegasi A) is a cool subgiant, an orange K-type star. It has begun to evolve off the main sequence and expand.

5477 Holmes, provisional designation , is a Hungaria asteroid and binary system from the innermost regions of the asteroid belt, approximately in diameter. It was discovered on 27 October 1989, by American astronomer Eleanor Helin at the Palomar Observatory in California. The presumed E-type asteroid is likely spherical in shape and has a short rotation period of 2.99 hours. It was named for American amateur astronomer Robert Holmes.

4786 Tatianina, provisional designation , is a bright background asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 13 August 1985, by Soviet astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula. It was named after Tatiana Somova, a friend of the discoverer. The E-/Xc-subtype has a short rotation period of 2.9 hours.

Healthcare of intersex persons is centered around what may be considered "cultural understandings of gender" or the binary system commonly used as gender. Surgeries and other interventions are often used for intersex persons to attempt to physically change their body to conform with one sex. It has been debated whether or not this practice is ethical. Much of this pressure to choose one sex to conform to is socially implemented.

The primary component is a binary system consisting of two nearly equal components with an orbital period of around and an angular separation of . It shows a combined stellar classification of B7/8V, which matches a B-type main-sequence star. The third component is a magnitude 10.0 star at a separation of with a mass similar to the Sun. It is orbiting the inner pair with a period of around .

This is a single- lined spectroscopic binary system, but the secondary has been detected using interferometry. It is a RS Canum Venaticorum variable system with eclipses. The total amplitude of variation is only about a thousandth of a magnitude. The secondary star is similar to the sun, presumably a main sequence star, while the primary is a giant star 25 times larger than the sun and two hundred times more luminous.

Blossite was first described for an occurrence in the “Y” fumarole in the summit crater of Izalco Volcano, El Salvador. There it occurs with several high-temperature minerals including: stoiberite, fingerite, ziesite, and mcbirneyite. The natural analogues of these compounds crystallize in the CuO-V2O5 binary system first studied by Brisi and Molinari (1958) and were first discovered as synthetic compounds. Blossite is the low temperature polymorph of ziesite, β-Cu2V2O7.

The maximum luminosity of an eclipsing binary system is equal to the sum of the luminosity contributions from the individual stars. When one star passes in front of the other, the luminosity of the system is seen to decrease. The luminosity returns to normal once the two stars are no longer in alignment. The first eclipsing binary star system to be discovered was Algol, a star system in the constellation Perseus.

The secondary star, HD 109749 B, is a K-type main sequence star with an apparent magnitude of 10.3. It has a mass of about and is located at a separation of 8.4 arcseconds, which corresponds to a projected separation of 490 AU. This star has the same proper motion as the primary and seems to be at the same distance, confirming they form a physical binary system.

Supernova-induced HVSs may also be possible, although they are presumably rare. In this scenario, a HVS is ejected from a close binary system as a result of the companion star undergoing a supernova explosion. Ejection velocities up to 770 km/s, as measured from the galactic rest frame, are possible for late-type B-stars. This mechanism can explain the origin of HVSs which are ejected from the galactic disk.

The orbital plane of the two stars is aligned to our line of sight, so each component eclipses the other when passing in front of it. In AD Andromedae this cycle repeats with a period 20 minutes less than one day. A cyclic variation of 14.3 years in the orbital period of this binary system has been reported, and this could be an effect of another body orbiting in this system.

Visual comparison of the sizes of Earth and the Moon (above right) and Pluto–Charon (below right) In astronomy, a double planet (also binary planet) is a binary system where both objects are of planetary mass. Binary asteroids with components of roughly equal mass are sometimes referred to as double minor planets. These include binary asteroids 69230 Hermes and 90 Antiope and binary Kuiper belt objects (KBOs) 79360 Sila–Nunam and .

1089 Tama, provisional designation , is an elongated Florian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 12 kilometers in diameter. It was discovered by Japanese astronomer Okuro Oikawa at the old Tokyo Astronomical Observatory () on 17 November 1927. The asteroid was named after the Tama River in Japan. Its minor-planet moon was discovered in December 2003 and measures approximately 9 kilometers.

Accessed on line July 9, 2008. the two components provide one of the best contrasting double stars in the sky due to their different colors. It is not known whether the two components β Cygni A and B are orbiting around each other in a physical binary system, or if they are merely an optical double. If they are a physical binary, their orbital period is probably at least 100,000 years.p.

32008 Adriángalád, provisional designation , is a background asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 29 April 2000, by astronomers with the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. The V-type asteroid has a rotation period of 3.0 hours. It was named for Slovak astronomer Adrián Galád.

The two stars form an eclipsing binary system (variable star designation: V1488 Cyg) similar to Algol. The orbital plane of the two stars is nearly aligned with the line of sight from the Earth, so that the giant star eclipses the secondary component once per orbit. During an eclipse, emission lines can be seen in the spectrum of this system. These originate in the stellar wind escaping from the giant star.

', provisional designations and , as well as periodic cometary number , is a kilometer-sized asteroid from the outer regions of the asteroid belt and the first "binary main-belt comet" ever discovered. belongs to the exclusive class of main-belt comets, which display properties of both comets and asteroids. It is also a synchronous binary system and potentially the slowest rotator known to exist. The object was discovered by Spacewatch in 2006.

This is a probable astrometric binary system. The visible component, Omicron Piscium A, is an evolved K-type giant star with a stellar classification of K0 III. At the estimated age of 390 million years, it is most likely (76% chance) on the horizontal branch, rather than the red- giant branch. As such, it is a red clump star that is generating energy through helium fusion at its core.

It is believed that Kleopatra's shape, rotation, and moons are due to an oblique impact perhaps 100 million years ago. The increased rotation would have elongated the asteroid and caused Alexhelios to split off. Cleoselene may have split off later, around 10 million years ago. Kleopatra is a contact binary – if it were spinning much faster, the two lobes would separate from each other, making a true binary system.

The two components of the binary system includes a K-type giant star and a G-type main sequence star. The primary star is estimated to be 1.8 times as massive and 13 times the diameter of the Sun. The secondary star is estimated to be similar to the Sun in size and mass. They orbit their common barycenter in a period precisely estimated to be 24.64877 days.

DENIS-P J082303.1-491201 (also known as DENIS J082303.1-491201, DE0823-49), is a binary system of two brown dwarfs, located away from the Earth. The system is located in the constellation Vela. The primary has a spectral class of L1.5, a mass of and a temperature of . The secondary is also a brown dwarf but with a spectral type of L5.5, a mass of , and a temperature of .

Isak's world has no name, since its inhabitants haven't conceived that there could be anywhere else. In fact, their world is a planet in a multiple-star system. Within that system, the planet orbits around Alpher, a yellow star like Earth's sun. Alpher and the smaller, cooler Bethe form a binary system, orbiting around each other but always separated by distances much greater than the orbit of the planet.

' , provisional designation , is a trans-Neptunian object and binary system that resides in the Kuiper belt. It is classified as a plutino and measures approximately 100 kilometers in diameter. It was discovered on 14 October 2007, by American astronomers Scott Sheppard and Chad Trujillo with the Subaru telescope at Mauna Kea Observatories in Hawaii, United States. It was later named after the twins Mors and Somnus from Roman mythology.

KSw 71 is a rapidly-spinning star in the constellation of Lyra. It is thought to have formed after two stars in a close binary system merged; its rotation has deformed it into an oblate spheroid shape. KSw 71 was discovered, alongside other pumpkin-shaped stars by NASA's Kepler and Swift missions and produces X-rays at more than 100 times the peak levels ever seen from the Sun.

This is an astrometric binary system with a period of 6.5 years (2,374 days) and an orbital eccentricity of 0.10. The visible component is an aging giant star of type G with a stellar classification of G9 IIIb Fe−0.5. The suffix notation indicates the spectrum displays a mild underabundance of iron. It has 1.29 times the mass of the Sun and has expanded to 9.3 times the Sun's radius.

HD 15558 A is a spectroscopic binary system containing at least two massive luminous class O stars. The primary is an O4.5 giant star with a surface temperature over 46,800 K. It has a mass of 152 and a luminosity of 660,000 , making it one of the most massive stars in the Milky Way Galaxy. The star loses 1.5×10−5 per year. The secondary is an O7V star.

It is 2.5 to 3 times as massive. It is unclear what stage of evolution the star is in. This is a spectroscopic binary, which means that the two stars have not been individually resolved using a telescope, but the presence of the companion has been inferred from measuring changes in the spectrum of the primary. The orbital period of the binary system is 4197.7 days (11.5 years).

' is a trans-Neptunian object and binary system from the classical Kuiper belt, located in the outermost region of the Solar System. The bright cubewano belongs to the cold population and measures approximately in diameter. It was first observed at Mauna Kea Observatory on 18 July 1999. Discovered in 2005, its minor-planet moon is just 3 kilometres smaller than its primary and has an orbital period of 84 days.

HR 6902 (also designated V2291 Oph) is a binary system located 790 light years away from the Sun in the Ophiuchus constellation. The system includes an orange bright giant star and a B-type main sequence star, forming an eclipsing binary of Zeta Aurigae type. The system is also surrounded by a warm circumstellar envelope and the spectra show silicon and carbon absorption up to a distance of 3.3 giant radii.

The two revolve around each other every 2.24 years. Farther afield is a binary system of two G-type main sequence stars, that would take 170,000 years to orbit the main pair if they are in fact related. Omicron Pegasi has a magnitude of 4.79. Located 300 ± 20 light-years distant from Earth, it is a white subgiant that has begun to cool, expand and brighten as it exhausts its core hydrogen fuel and moves off the main sequence. Pi1 and Pi2 Pegasi appear as an optical double to the unaided eye as they are separated by 10 arcminutes, and are not a true binary system. Located 289 ± 8 light-years distant, Pi1 is an ageing yellow giant of spectral type G6III, 1.92 times as massive and around 200 times as luminous as the Sun. Pi2 is a yellow-white subgiant that is 2.5 times as massive as the Sun and has expanded to 8 times the Sun's radius and brightened to 92 times the Sun's luminosity.

A phase diagram for a binary system displaying a eutectic point Thermodynamics is concerned with heat and temperature and their relation to energy and work. It defines macroscopic variables, such as internal energy, entropy, and pressure, that partly describe a body of matter or radiation. It states that the behavior of those variables is subject to general constraints common to all materials. These general constraints are expressed in the four laws of thermodynamics.

Pi Ceti, Latinized from π Ceti, is the Bayer designation for a star system in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of 4.238. Based upon an annual parallax shift of 8.30 mas, it is located around 393 light years from the Sun. This is a single- lined spectroscopic binary system with a nearly circular orbit and a period of 7.45 years.

In 1947, Hector Garcia was elected president of the local chapter of LULAC. In the same year he was hospitalized with life-threatening acute nephritis. While recuperating, he heard the local superintendent of the school district talking about the racial segregation in his district. Southern states had established a binary system, classifying all people as mainly either black or white, or Hispanic in some states like Texas, and segregating public facilities by race.

Eta Ursae Minoris is about one billion years old and has an estimated 1.35 times the mass of the Sun. It has a high rate of spin with a projected rotational velocity of 84.8 km/s. These coordinates mark a source of X-ray emission with a luminosity of . Eta Ursae Minoris may form a wide binary system with a magnitude 15.3 companion star, located at an angular separation of 228.5 arc seconds.

A large number of binary systems with non-radially pulsating members were observed by CoRoT. Some of them, which were eclipsing binaries with members of γ Doradus type, were discovered during CoRoT runs. The eclipse phenomenon plays a key role since global parameters can immediately follow, bringing invaluable constraints, in addition to the seismic ones, to stellar modeling. # AU Monocerotis: This semi-detached binary system contains a Be star interacting with its G star companion.

Thereafter a close binary system may spend another million years in the mass transfer stage (possibly forming persistent nova outbursts) before the conditions are ripe for a Type Ia supernova to occur. A long-standing problem in astronomy has been the identification of supernova progenitors. Direct observation of a progenitor would provide useful constraints on supernova models. As of 2006, the search for such a progenitor had been ongoing for longer than a century.

When a star passes near a binary system, the orbit of the latter pair tends to contract, releasing energy. Only after the primordial supply of binaries is exhausted due to interactions can a deeper core collapse proceed. In contrast, the effect of tidal shocks as a globular cluster repeatedly passes through the plane of a spiral galaxy tends to significantly accelerate core collapse. The different stages of core-collapse may be divided into three phases.

8116 Jeanperrin, provisional designation , is a Florian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 17 April 1996, by Belgian astronomer Eric Elst at the La Silla Observatory in northern Chile. The likely stony S-type asteroid has a rotation period of 3.62 hours and a nearly round shape. It was named for French physicist and Nobel laureate Jean Baptiste Perrin.

2658 Gingerich, provisional designation , is a background asteroid and a suspected synchronous binary system from the outer regions of the asteroid belt, approximately in diameter. It was discovered on 13 February 1980, by astronomers of the Harvard College Observatory at the Agassiz Station near Harvard, Massachusetts, in the United States. The presumed carbonaceous C-type asteroid has a short rotation period of 2.9 hours. It was named after Harvard astronomer Owen Gingerich.

7369 Gavrilin, provisional designation , is a stony Phocaean asteroid, sizable Mars-crosser, and binary system on an eccentric orbit from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 13 January 1975, by Russian astronomer Tamara Smirnova at the Crimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula. The assumed S-type asteroid has a long rotation period of 49.1 hours. It was named after Russian composer Valery Gavrilin.

1453 Fennia, provisional designation , is a stony Hungaria asteroid and synchronous binary system from the innermost regions of the asteroid belt, approximately 7 kilometers in diameter. Discovered by Yrjö Väisälä at the Turku Observatory in 1938, the asteroid was later named after the Scandinavian country of Finland. The system's minor-planet moon was discovered in 2007. It has a derived diameter of 1.95 kilometers and is orbiting its primary every 23.55 hours.

During the photometric observation in 2007, it was also revealed, that Pogson is an asynchronous binary system with a minor-planet moon in its orbit. The mutual eclipse and occultation events showed that the companion, provisionally designated , orbits its primary every 24.24 hours. Based on a secondary-to-primary diameter ratio of 0.32 or larger, Johnston's archive estimates a diameter of 2.52 kilometers for the satellite, separated by 8 kilometers from its primary.

6244 Okamoto, provisional designation , is a background asteroid and binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 20 August 1990, by Japanese astronomer Tsutomu Seki at the Geisei Observatory in Kōchi, Japan, and later named after Japanese school teacher Hiroshi Okamoto. The presumed S-type asteroid has a short rotation period of 2.9 hours. The discovery of its minor-planet moon was announced in October 2006.

2726 Kotelnikov, provisional designation , is a stony Koronian asteroid from the outer regions of the asteroid belt, approximately in diameter. It was discovered on 22 September 1979, by Soviet astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnij on the Crimean peninsula. The S-type asteroid has a rotation period of 4.91 hours and is a suspected binary system. The asteroid was named for Soviet scientist and pioneer in radar astronomy, Vladimir Kotelnikov.

Altitude of Tiangong-1 during its final year of uncontrolled reentry. In orbital mechanics, decay is a gradual decrease of the distance between two orbiting bodies at their closest approach (the periapsis) over many orbital periods. These orbiting bodies can be a planet and its satellite, a star and any object orbiting it, or components of any binary system. Orbits do not decay without some friction-like mechanism which transfers energy from the orbital motion.

As of 1996, there is one cupronickel and forty cupronickel-clad-copper commemorative coin series. On September 15, 2005, the Royal Thai Mint began minting two-baht coins to complete the binary system in Thailand's coinage. That is, each successive denomination is worth twice, or roughly twice, as much as the previous one. Thai coin denominations in general circulation are now 25 satang, 50 satang, 1 baht, 2 baht, 5 baht, and 10 baht.

This is a single- lined spectroscopic binary system with an orbital period of 28.7 years and an eccentricity of 0.65. The primary member, designated component A, is an orange-hued (K–type) bright giant with a stellar classification of K1II. The star is around 50 million years old with 7 times the mass of the Sun. Having exhausted the supply of hydrogen at its core, it has expanded to roughly 56 times the Sun's radius.

A compact binary circle packing with the most similarly sized circles possible. It is also the densest possible packing of discs with this size ratio (ratio of 0.6375559772 with packing fraction (area density) of 0.910683). There are also a range of problems which permit the sizes of the circles to be non-uniform. One such extension is to find the maximum possible density of a system with two specific sizes of circle (a binary system).

' is a sub-kilometer asteroid and synchronous binary system, classified as near-Earth object and potentially hazardous asteroid of the Apollo group. It was discovered on 31 January 2008, by the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, United States. The eccentric asteroid measures approximately 600 meters in diameter and has a composition of a basaltic achondrite. In 2008, its minor-planet moon, designated , was discovered by radar astronomers.

Griffin (2012) found this to be a single-lined spectroscopic binary system with an orbital period of and an eccentricity of 0.23. The a sin i value for the primary component is , where a is the semimajor axis and i is the (unknown) orbital inclination. This value provides a lower bound for the actual semimajor axis. The visible component is an evolved K-type giant star with a stellar classification of K5 III.

3782 Celle, provisional designation , is a bright Vestian asteroid and asynchronous binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 3 October 1986, by Danish astronomer Poul Jensen at the Brorfelde Observatory in Denmark and named after the German city of Celle. The V-type asteroid has a rotation period of 3.84 hours. The discovery of its 2.3-kilometer minor-planet moon was announced in 2003.

Pi Piscis Austrini is moving through the galaxy at a velocity of 16.3 km/s relative to the Sun. Its projected galactic orbit carries it between 24,000 and 37,500 light-years from the center of the galaxy. This is a single-lined spectroscopic binary system with an orbital period of 178.3 days and an eccentricity of 0.53. The primary component is an F-type main-sequence star with a stellar classification of .

See chapter 8 of and . A treatment that is more thorough, yet involves only comparatively little mathematics can be found in . There are several properties that make black holes the most promising sources of gravitational waves. One reason is that black holes are the most compact objects that can orbit each other as part of a binary system; as a result, the gravitational waves emitted by such a system are especially strong.

Tau Cygni, Latinised from τ Cygni, is a binary star system in the constellation Cygnus, approximately 69 light years away from Earth. This visual binary system has a period of 49.6 years. The main star, 4th magnitude GJ 822.1 A, is a yellowish white subgiant star of the spectral type F2IV. It therefore has a surface temperature of 6,000 to 7,500 kelvins and is larger, hotter, and several times as bright as the Sun.

This is an astrometric binary system. The primary has a stellar classification of F2 III, suggesting that it is a giant star. Despite being an evolved star with four times the radius of the Sun, it is spinning rapidly with a projected rotational velocity of 139.6 km/s. This is causing a pronounced equatorial bulge, with the radius of the star along the equator being 24% greater than the radius at the poles.

This is a double star and possible binary system. The primary component has a stellar classification of G2 Ib/II, which places it on the borderline between the bright giant and lower luminosity supergiant stars. It has passed the first dredge-up and may be undergoind Cepheid-like pulsations. With more than four times the mass of the Sun, this is an evolved star that has reached its current stage after only 135 million years.

WR 104 is a triple star system located about from Earth. The primary star is a Wolf–Rayet star, abbreviated as WR, with a B0.5 main sequence star in close orbit and another more distant fainter companion. The WR star is surrounded by a distinctive spiral Wolf–Rayet nebula, often referred to as a pinwheel nebula. The rotational axis of the binary system, and likely of the two closest stars, is directed approximately towards Earth.

Kappa Centauri (κ Cen, κ Centauri) is a binary star in the southern constellation of Centaurus. With an apparent visual magnitude of +3.14, it can be viewed with the naked eye on a dark night. Parallax measurements place it at an estimated distance of from Earth. This is a spectroscopic binary system where the presence of an orbiting companion is revealed by shifts in the absorption lines caused by the Doppler effect.

The system is located about 98 light years away from the Sun based on parallax, and is drifting further away with a radial velocity of +16 km/s. It is a potential member of the Tucana–Horologium stellar kinematic group. This is a wide binary system with a projected separation of . Two sets of low quality orbital elements have been computed for this system, yielding periods of and , and eccentricities of 0.150 and 0.485, respectively.

3703 Volkonskaya, provisional designation , is a Vestian asteroid and asynchronous binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 9 August 1978, by Soviet astronomers Lyudmila Chernykh and Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula. It was named by the discoverers after the Russian princess Mariya Volkonskaya. The V-type asteroid has a rotation period of 3.2 hours.

Iota Arietis (ι Ari, ι Arietis) is the Bayer designation for a binary star system in the northern constellation of Aries. It has an apparent visual magnitude of 5.117; bright enough to be dimly seen with the naked eye. Parallax measurements made during the Hipparcos mission yield an estimated distance of from Earth. This is a spectroscopic binary system with an orbital period of 1,568 days (4.3 years) and an eccentricity of 0.36.

16525 Shumarinaiko, provisional designation , is a stony Nysian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 14 February 1991, by Japanese astronomers Kin Endate and Kazuro Watanabe at the Kitami Observatory on the island of Hokkaidō in northern Japan. The asteroid was named after the Japanese Lake Shumarinai. Its sub-kilometer sized minor-planet moon was discovered in 2013.

Pi Cassiopeiae, Latinized from π Cassiopeiae, is a close binary star system in the constellation Cassiopeia. It is visible to the naked eye with an apparent visual magnitude of +4.949. Based upon an annual parallax shift of 18.63 mas as seen from Earth, this system is located about 175 light years from the Sun. This is a double-lined spectroscopic binary system with an orbital period of nearly two days in a circular orbit.

The cluster may prove to be the galaxy's richest in terms of RR Lyrae variables. It has six binary millisecond pulsars, including one (COM6266B) that is displaying eclipsing behavior from gas streaming off its companion. There are multiple X-ray sources, including 50 within the half-mass radius. 47 blue straggler candidates have been identified, formed from the merger of two stars in a binary system, and these are preferentially concentrated near the core region.

This is a single-lined spectroscopic binary system with an orbital period of 576 days and an eccentricity of 0.3. The a sin i value for the primary is , where a is the semimajor axis and i is the (unknown) orbital inclination. The provides a minimum value for the actual semimajor axis. The visible component is a red giant star and has been defined as a standard star for the stellar classification of K6 IIIa.

In an eclipsing binary system, the 16.7 days period is also the orbital period. The two stars are of spectral type F5 and G3, and they have almost the same mass. They could be so close that mass transfer is occurring in the system, changing the orbital period in time. An alternative explanation could be the presence in the system of two low mass companions with orbital periods of 50 and 70 years, respectively.

The asteroid's proper name comes from Greek mythology, but it is disputed whether this is Antiope the Amazon or Antiope the mother of Amphion and Zethus. Since the discovery of Antiope's binary nature, the name "Antiope" technically refers to the slightly larger of the two components, with the smaller component bearing the provisional designation S/2000 (90) 1. However, the name "Antiope" is also used to refer to the binary system as a whole.

1313 Berna, provisional designation , is a background asteroid and synchronous binary system from the Eunomian region in the central asteroid belt, approximately in diameter. It was discovered on 24 August 1933, by Belgian astronomer Sylvain Arend at the Uccle Observatory in Belgium. The assumed S-type asteroid has a longer-than average rotation period of 25.5 hours and is likely elongated in shape. It was named for the Swiss capital of Bern.

The success of Zuse's Z3 is often attributed to its use of the simple binary system. This was invented roughly three centuries earlier by Gottfried Leibniz; Boole later used it to develop his Boolean algebra. Zuse was inspired by Hilbert's and Ackermann's book on elementary mathematical logic (cf. Principles of Mathematical Logic). In 1937, Claude Shannon introduced the idea of mapping Boolean algebra onto electronic relays in a seminal work on digital circuit design.

The Indian scholar Pingala (c. 2nd century BC) developed a binary system for describing prosody.W. S. Anglin and J. Lambek, The Heritage of Thales, Springer, 1995, He used binary numbers in the form of short and long syllables (the latter equal in length to two short syllables), making it similar to Morse code.Binary Numbers in Ancient IndiaMath for Poets and Drummers (pdf, 145KB) They were known as laghu (light) and guru (heavy) syllables.

22899 Alconrad, provisional designation , is a Koronian asteroid and binary system from the outer region of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 11 October 1999, by Croatian astronomers Korado Korlević and Mario Jurić at the Višnjan Observatory, Croatia. When its minor-planet moon was discovered in 2003, it was the smallest known main-belt asteroid to possess a satellite. It was later named after American astronomer Albert R. Conrad.

156–157 In The Book of Urizen, Los is constantly at struggle with Urizen to control the world and the two represent opposites. However, this was to later change when Blake added two other beings in his later work.Bentley 2003 pp. 198–199 In the early works, however, the binary system is possibly similar to the imaginative and reason sides that Blake divided his own mind and a struggle between the two.

M82 X-2 is an X-ray pulsar located in the galaxy Messier 82, approximately 12 million light-years from Earth. It is exceptionally luminous, radiating energy equivalent to approximately ten million Suns. This object is part of a binary system: If the pulsar is of an average size, , then its companion is at least . On average, the pulsar rotates every 1.37 seconds, and revolves around its more massive companion every 2.5 days.

It is a spectroscopic binary system, one estimate placing the distance between the pair of stars as 0.21 astronomical units (AU), or half the distance between Mercury and the Sun. The two stars rotate around each other in a mere 11 days and 18 hours. The star system is located around 180 light years away from Earth. With an apparent magnitude of 3.43, Beta Pavonis is the second-brightest star in the constellation.

Alphard's spectrum shows a mild excess of barium, an element that is normally produced by the s-process of nucleosynthesis. Typically a barium star belongs to a binary system and the anomalies in abundances are explained by mass transfer from a companion white dwarf star. Precise radial velocity measurements have shown variations in the stellar radial velocities and spectral line profiles. The oscillations are multi-periodic with periods from several hours up to several days.

A Digital Spectral Classification Atlas, R. O. Gray, 34. Unusual Stellar Spectra III: two emission-line stars T CrB is a binary system containing a large cool component and a smaller hot component. The cool component is a red giant which is transferring material to the hot component. The hot component is a white dwarf surrounded by an accretion disc, all hidden inside a dense cloud of material from the red giant.

' is a sub-kilometer asteroid and near-Earth object of the Apollo group, at least in diameter. It was first observed on 3 January 2016, by the WISE telescope with precovery images found back in 2012. The potentially hazardous asteroid is a binary system with a minor-planet moon in its orbit. The discovery was made by astronomers at Arecibo Observatory on 4 January 2019, while was passing within of the Earth.

61 Cygni A's long-term stability led to it being selected as an "anchor star" in the Morgan–Keenan (MK) classification system in 1943, serving as the K5 V "anchor point" since that time. Starting in 1953, 61 Cygni B has been considered a K7 V standard star (Johnson & Morgan 1953, Keenan & McNeil 1989). alt=Diagram showing the size comparison between the two stars of the 61 Cygni binary system and the Sun.

Kunz's photoelectric cells were many times more sensitive than what was available commercially and therefore able to detect faint star light. In 1915, Stebbins used the new photometers to examine Beta Lyrae, a more irregular binary system. The new equipment allowed observations of increasingly faint stars. Stebbins work was recognized with the American Academy of Arts and Sciences' Rumford Prize in 1913, and the United States National Academy of Sciences' Henry Draper Medal in 1915.

Based on measured changes in the star's motion, this is most likely an astrometric binary system. The visible component is an A-type main-sequence star with a stellar classification of A3 V. It is catalogued as an Alpha2 Canum Venaticorum variable with the designation GN Com. Rensom (1990) listed it as a suspected Am star. The system is a source of X-ray emission, which may be coming from the companion.

The fact that VV Cephei is an eclipsing binary system was discovered by American astronomer Dean McLaughlin in 1936. VV Cephei experiences both primary and secondary eclipses during a 20.3 year orbit. The primary eclipses totally obscure the hot secondary star and last for nearly 18 months. Secondary eclipses are so shallow that they have not been detected photometrically since the secondary obscures such a small proportion of the large cool primary star.

The radial velocity for Eta Tucanae displays strong oscillations, suggesting this is a spectroscopic binary system. A companion was directly detected in 2014, but this result has some unexplained anomalies. The primary component is an A-type main-sequence star with a stellar classification of A1V. It is spinning rapidly with a projected rotational velocity of 190 km/s, giving it an equatorial bulge that is 15% larger than the polar radius.

ET Andromedae is a binary star system star in the northern constellation of Andromeda. It has an apparent visual magnitude of 6.48, placing it at the nominal limit for visibility with the naked eye. The distance to this system can be estimated from its annual parallax shift of , which yields a value of 602 light years. Variations in the radial velocity of this star suggest it is a single-lined spectroscopic binary system.

HD 195564 is the Henry Draper Catalogue designation for a star in the southern constellation of Capricornus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.65. Parallax measurements from the Hipparcos spacecraft give us an estimate of its distance as around 80 light years. This appears to be a wide binary system as a faint companion star shares a common proper motion with the brighter primary component.

Its companion, HD 28254 B, has a visual apparent magnitude of 13.8 and is located at a separation of 4.3 arcseconds. The two stars have maintained the same separation through time, indicating that they form a physical binary system. Furthermore, the radial velocity of the primary shows signs of orbital motion. From its brightness, the companion star is probably a red dwarf with spectral type between M0V and M2V, with about 48% the solar mass.

However, the team was unable to confirm the planet until extensive follow-up observations, as high-resolution imaging resolved the star Kepler-14 as a closely orbiting binary system. The Kepler team would have not noticed that Kepler-14 was a binary star based solely on initial radial velocity measurements (a standard method for confirming a planet's existence), and found that if they had not realized this, their data on Kepler-14b would have been very inaccurate.

Under Dutch law, one credit represents 28 hours of work and 60 credits represents one year of full-time study. Both systems have been adopted to improve international recognition and compliance. Despite these changes, the binary system with a distinction between research-oriented education and professional higher education remains in use. These three types of degree programmes differ in terms of the number of credits required to complete the programme and the degree that is awarded.

At its peak, the strip was carried in 600 newspapers. It was noted for its scientific accuracy, and the Captain explained the binary system to readers when computers were in their infancy. In 1949, Turner did extensive research into alcoholism in order to write a strip sequence on the rehabilitation of drunkard Gig Wilty. The story arc brought Turner praise from many members of Alcoholics Anonymous."Captain Easy creator dies", The Miami News, March 1, 1988.

HD 59686 is a binary star system in the northern constellation of Gemini. It is visible to the naked eye as a dim point of light with an apparent visual magnitude of +5.45. The distance to this system is approximately 292 light years based on parallax, but it is drifting closer with a radial velocity of −34 km/s. This is a single-lined spectroscopic binary system with an orbital period of and a high eccentricity of 0.73.

NASA is planning to send a spacecraft Double Asteroid Redirection Test (DART) in July 2021. The spacecraft will crash-land on Dimorphos in September 2022. The collision is expected to bring the Dimorphos and Didymos closer to each other so that Dimorphos' orbits is shortened by 10 to 20 minutes. Then the European Space Agency will send its probe named Hera to Dimorphos in 2024 to study the new path of movement of the binary system.

Leibniz's writings on Chinese civilization are collected and translated in Cook and Rosemont (1994), and discussed in Perkins (2004). Leibniz communicated his ideas of the binary system representing Christianity to the Emperor of China, hoping it would convert him. Leibniz was the only major Western philosopher of the time who attempted to accommodate Confucian ideas to prevailing European beliefs. Leibniz's attraction to Chinese philosophy originates from his perception that Chinese philosophy was similar to his own.

The stars are so close that they are in contact with each other (overcontact binary) and are classed as a Beta Lyrae variable as their light varies from Earth as they eclipse each other. The system ranges from apparent magnitude 8.17 to 8.75 over around 1.4 days. Also known as Nova Muscae 1983, GQ Muscae is a binary system consisting of a white dwarf and small star that is about 10% as massive as the Sun.

LSI+61°303 is a possible example of a Be/X-ray binary star. It is a periodic, radio-emitting binary system that is also the gamma-ray source, CG135+01. It is also a variable radio source characterized by periodic, non- thermal radio outbursts with a period of 26.496 d. The 26.5 d period is attributed to the eccentric orbital motion of a compact object, possibly a neutron star, around a rapidly rotating B0 Ve star.

5143 Heracles, provisional designation , is a highly eccentric, rare-type asteroid and synchronous binary system, classified as near-Earth object of the Apollo group, approximately 4.8 kilometers in diameter. The asteroid was discovered on 7 November 1991, by American astronomer Carolyn Shoemaker at Palomar Observatory in California, United States. It is named for the Greek divine hero Heracles. It has an Earth minimum orbit intersection distance of and is associated with the Beta Taurids daytime meteor shower.

For some time, Teide 1 was the smallest known object outside the Solar System that had been identified by direct observation. Since then, over 1,800 brown dwarfs have been identified, even some very close to Earth like Epsilon Indi Ba and Bb, a pair of brown dwarfs gravitationally bound to a Sun-like star 12 light-years from the Sun, and Luhman 16, a binary system of brown dwarfs at 6.5 light-years from the Sun.

Despite having different distances when measured by the HIPPARCOS satellite, the two stars share a common proper motion and appear to be a natural binary system. Located 181 ± 2 light-years from Earth, Alpha Cancri (Acubens) is a multiple star with a primary component an apparent white main sequence star of spectral type A5 and magnitude 4.26. The secondary is of magnitude 12.0 and is visible in small amateur telescopes. Its common name means "the claw".

Theorized in 1988, and observed in 2005, there are stars moving faster than the escape velocity of the Milky Way, and are traveling out into intergalactic space. There are several theories for their existence. One of the mechanisms would be that the supermassive black hole at the center of the Milky Way ejects stars from the galaxy at a rate of about one every hundred thousand years. Another theorized mechanism might be a supernova explosion in a binary system.

During the second photometric observation, it was discovered that is a probable/possible asynchronous binary system with a minor-planet moon orbiting it every 7.0035 hours, or twice this period solution. The moon's provisional designation is . The system has an estimated secondary-to-primary mean- diameter ratio of more than 0.3, which translates into a diameter of 270 meter for the satellite. The "Johnston's archive" also estimates that the moon's orbit has a semi-major axis of 1.4 kilometers.

Gliese 829 is a double-lined spectroscopic binary system of two red dwarf stars in the constellation of Pegasus. They have a high proper motion of 1.08 arcseconds per year along a position angle of +69.58°. Based upon parallax measurements, the stars are at a distance of about 22 light years from the Sun. The system will make its closest approach to the Sun around 91,000 years from now when it achieves a perihelion distance of .

Kepler-453b is a transiting circumbinary exoplanet in the binary-star system Kepler-453. It orbits the binary system in the habitable zone every 240.5 days. The orbit of the planet is inclined relative to the binary orbit therefore precession of the orbit leads to it spending most of its time in a non-transiting configuration. By the time the TESS and PLATO spacecraft are available for follow up observations it will no longer be transiting.

HY Velorum is a binary star system in the southern constellation of Vela. It is a dim star but visible to the naked eye with an apparent visual magnitude of 4.83. The distance to this system, as estimated from its annual parallax shift of , is 460 light years. HY Vel most likely forms a gravitationally bound pair with the magnitude 5.45 binary system KT Vel (HD 74535); both are members of the IC 2391 open cluster.

Astrometric measurements of the star show changes in motion that may indicate it is a member of a close binary system. This is an A-type main-sequence star with a stellar classification of A3 V. It is a suspected chemically peculiar star and formerly a candidate Lambda Boötis star. The status as a Lambda Boötis star was reviewed and changed to non-member in 2015. It is spinning rapidly with a projected rotational velocity of 196 km/s.

CFBDSIR J145829+101343 (designation abbreviated to CFBDSIR 1458+10, or CFBDSIR J1458+1013) is a binary system of two brown dwarfs of spectral classes T9 + Y0 orbiting each other, located in constellation Boötes about 104 light-years away from Earth. The smaller companion, CFBDSIR 1458+10B, has a surface temperature of approx 370 K (≈100 °C) and used to be known as the coolest known brown dwarf until the discovery of WISE 1828+2650 in August 2011.

At this distance, the brightness of the system is diminished by 0.065 in visual magnitude from extinction caused by interstellar gas and dust. This is a spectroscopic binary system where the presence of an orbiting companion is revealed by shifts in the spectral lines caused by the Doppler effect. The primary component is a giant star with a stellar classification of G8 III. The secondary is following a circular orbit with a period of 205.2 days.

It is moving closer to the Earth with a heliocentric radial velocity of −30 km/s. The motion of the star over time suggests some displacement, which may indicate it is a close binary system. This is an aging giant star with a stellar classification of K5 III, which indicates it has exhausted the supply of hydrogen at its core and expanded off the main sequence. The measured angular diameter of this star, after correcting for limb darkening, is .

Java and Pascal programs are also studied along with Logic operations using different number bases. Seniors may either take Computer Engineering, where they are taught hardware maintenance and repair; Logic, for students interested in integrated and digital circuits which operate in the binary system; or Basic Electronics. Seniors take Electronics, where they learn the components and processes of an electronic circuit. They are required to build an electronic device and a defense follows at the end of their course.

Nu Cancri, Latinized from ν Cancri, is a binary star in the zodiac constellation of Cancer. It is faintly visible to the naked eye with an apparent visual magnitude of +5.46. Based upon an annual parallax shift of 8.31 mas as seen from the Earth, the star is located roughly 390 light years from the Sun. This is a single-lined spectroscopic binary system with an orbital period of 3.8 years and an eccentricity of 0.35.

The discovery of the pair was announced in a 2006 Science article by Ray Jayawardhana and Valentin D. Ivanov . The objects were discovered using telescopes of the European Southern Observatory's New Technology Telescope in La Silla, Chile. The masses were originally reported to be lower, at 14 and 7 Jupiter masses, which would have made the smaller object a planetary-mass object, or planemo. The system was announced as the first reported binary system of objects this small.

To prove his point he had to add 1400 years to the time period that existed between Creation and the birth of Abraham. This however did not satisfy the European intelligentsia or the missionaries in China. His work nevertheless had a major impact in other areas of European science.University of Barcelona website Leibniz, for example, was able to establish, after communicating with the Jesuits, that the binary system he had invented also existed in the Yijing.

66391 Moshup , provisional designation , is a binary asteroid, classified as a near-Earth object and potentially hazardous asteroid of the Aten group, approximately 1.3 kilometers in diameter. It was discovered on 20 May 1999, by Lincoln Near-Earth Asteroid Research (LINEAR) at the Lincoln Laboratory's Experimental Test Site in Socorro, New Mexico, United States. It is also a Mercury-crosser and the closest known binary system to the Sun with a perihelion of just 0.2 AU.

This is a single-lined spectroscopic binary system with an orbital period of 4.3 days and a nearly circular orbit with an eccentricity of 0.01. The primary, component A, is an Am star with a stellar classification of kA5hF0mF2. This complex notation indicates that the spectral type determined solely from the calcium K line would be A5, the spectral type determined from other metallic lines would be F2, and the type determined from hydrogen lines would be F0.

Water waves, sound waves, and electromagnetic waves are able to carry energy, momentum, and angular momentum and by doing so they carry those away from the source. Gravitational waves perform the same function. Thus, for example, a binary system loses angular momentum as the two orbiting objects spiral towards each other—the angular momentum is radiated away by gravitational waves. The waves can also carry off linear momentum, a possibility that has some interesting implications for astrophysics.

Tau1 Arietis, Latinized from τ1 Arietis, is the Bayer designation for a triple star system in the northern constellation of Aries. Based upon an annual parallax shift of 6.41 mas, it is approximately distant from Earth. The combined apparent visual magnitude is 5.27, making it faintly visible to the naked eye. The inner pair form an eclipsing binary system, with the brightness of the pair decreasing by 0.06 in magnitude during an eclipse of the primary.

69230 Hermes is a sub-kilometer sized asteroid and binary system on an eccentric orbit, classified as a potentially hazardous asteroid and near-Earth object of the Apollo group, that passed Earth at approximately twice the distance of the Moon on 30 October 1937. The asteroid was named after Hermes from Greek mythology. It is noted for having been the last remaining named lost asteroid, rediscovered in 2003. The S-type asteroid has a rotation period of 13.9 hours.

The system is drifting further away with a radial velocity of +24 km/s. This is a single-lined spectroscopic binary system with an orbital period of and an eccentricity of 0.12. The visible component is an F-type main sequence star with a stellar classification of , where the suffix notation indicates mild but anomalous underabundances of iron and the cyano radical. The secondary is most likely a helium white dwarf with 0.47 times the mass of the Sun.

Tick–tock was a production model adopted in 2007 by chip manufacturer Intel. Under this model, every microarchitecture change (tock) was followed by a die shrink of the process technology (tick). It was replaced by the process–architecture–optimization model, which was announced in 2016 and is like a tick–tock cycle followed by an optimization phase. As a general engineering model, tick-tock is a model that refreshes one side of a binary system each release cycle.

In the UK a binary system of higher education emerged consisting of universities (research orientation) and polytechnics (engineering and applied science and professional practice orientation). Polytechnics offered university equivalent degrees mainly in STEM subjects from bachelor's, master's and PhD that were validated and governed at the national level by the independent UK Council for National Academic Awards. In 1992 UK polytechnics were designated as universities which meant they could award their own degrees. The CNAA was disbanded.

Because the percentage of each constituent can be varied, with any mixture the entire range of possible variations is called a system. In this respect, all of the various forms of an alloy containing only two constituents, like iron and carbon, is called a binary system, while all of the alloy combinations possible with a ternary alloy, such as alloys of iron, carbon and chromium, is called a ternary system.Bauccio, Michael (1003) ASM metals reference book. ASM International. .

Two binary abacuses constructed by Dr. Robert C. Good, Jr., made from two Chinese abacuses The binary abacus is used to explain how computers manipulate numbers. The abacus shows how numbers, letters, and signs can be stored in a binary system on a computer, or via ASCII. The device consists of a series of beads on parallel wires arranged in three separate rows. The beads represent a switch on the computer in either an "on" or "off" position.

Binary asteroid 243 Ida with its small minor-planet moon, Dactyl, as seen by Galileo A binary asteroid is a system of two asteroids orbiting their common barycenter. The binary nature of 243 Ida was discovered when the Galileo spacecraft flew by the asteroid in 1993. Since then numerous binary asteroids and several triple asteroids have been detected. The mass ratio of the two components – called the "primary" and "secondary" of a binary system – is an important characteristic.

HR Carinae has a temperature around 21,000K when quiescent and the spectrum is of an early B hypergiant, but in outburst it cools to below 8,000K. HR Carinae is a lot like Eta Carinae, both luminous blue variables, and both surrounded by ejected material. HR Carinae is also likely to be a binary system with a similar separation, period, and ratio of component sizes to Eta Carinae. However, the Eta Carinae system is more massive and more luminous.

In order to work out the masses of the components of a visual binary system, the distance to the system must first be determined, since from this astronomers can estimate the period of revolution and the separation between the two stars. The trigonometric parallax provides a direct method of calculating a star's mass. This will not apply to the visual binary systems, but it does form the basis of an indirect method called the dynamical parallax.

This is a spectroscopic binary system, consisting of an orbiting pair of stars that have not been individually resolved with a telescope. Their orbital period is 257.8 days and the eccentricity is 0.17. The pair form an eclipsing binary of the Beta Lyrae type and a period of 130.5 days, or one half of their orbital period. The eclipse of the primary component causes a decline of 0.04 magnitudes, while the secondary eclipse reduces the magnitude by 0.03.

V838 Monocerotis, a variable red supergiant star, had an outburst starting on January 6, 2002; in February of that year, its brightness increased by a factor of 10,000 in one day. After the outburst was over, the Hubble Space Telescope was able to observe a light echo, which illuminated the dust surrounding the star. Monoceros also contains Plaskett's Star, a massive binary system whose combined mass is estimated to be that of almost 100 solar masses.

R Aquarii (R Aqr) is a variable star in the constellation Aquarius. R Aquarii is a symbiotic star believed to contain a white dwarf and a Mira-type variable in a binary system. The orbital period is approximately 44 years. The main Mira-type star is a red giant, and varies in brightness by a factor of several hundred and with a period of slightly more than a year; this variability was discovered by Karl Ludwig Harding in 1810.

In a physical or geochemical system, a solvus is a line (binary system) or surface (ternary system) on a phase diagram which separates a homogeneous solid solution from a field of several phases which may form by exsolution or incongruent melting. The line determines a solid solubility limit which changes as a function of temperature. It is a locus of points on the equilibrium diagram. An example is the formation of perthite when an alkali feldspar is cooled down.

The Pale One is either a large moon or a double planet. The other four stars are much farther away from Alpher than Bethe, and spread around Alpher so that evidently there is no place on the planet where all are below the horizon. Gamow and Dalton each orbit by themselves, while Ephron and Zwicky are another binary system. Gamow is well north of the equator, while Dalton and "the Twinned Ones" are well to the south.

In 2000, this distance was revised to after correcting for probable errors. The Gaia spacecraft later measured the parallax of the star leading to an accurate distance of parsecs. The nova outburst can be explained by a white dwarf that is accreting matter from a companion; most likely a low-mass main sequence star. This close binary system has an orbital period of 1.47 hours, which is one of the shortest periods of the known classical nova.

5 Cancri is a single star in the zodiac constellation of Cancer, located around 520 light years away from the Sun. It is just visible to the naked eye under good seeing conditions as a dim, blue-white hued star with an apparent visual magnitude of 5.99. This object is moving closer to the Sun with a heliocentric radial velocity of −10 km/s. At one point this was thought to be a spectroscopic binary system.

In addition, the variable x is the distance term. It is important to note that this equation only holds in situations where the total concentration remains constant. For a binary system this is defined by C1 \+ C2 = C, where C is the overall concentration of the system that remains constant, and C1 and C2 are the corresponding component's concentration. This is equivalent to saying that the partial molar volumes of the two components are constant and equal.

HD 80606 and HD 80607 are two stars comprising a binary star system. They are approximately 217 light-years away in the constellation of Ursa Major. Both stars orbit each other at an average distance of 1,200 astronomical units. The binary system is listed as Σ1341 in the Struve Catalogue of Double Stars, however this designation is not in wide use and the system is usually referred to by the HD designations of its constituent stars.

In astrophysics the chirp mass of a compact binary system determines the leading-order orbital evolution of the system as a result of energy loss from emitting gravitational waves. Because the gravitational wave frequency is determined by orbital frequency, the chirp mass also determines the frequency evolution of the gravitational wave signal emitted during a binary's inspiral phase. In gravitational wave data analysis it is easier to measure the chirp mass than the two component masses alone.

RZ Pyxidis is eclipsing binary system in the constellation Pyxis, made up of two young stars less than 200,000 years old. Both are hot blue-white stars of spectral type B7V and are around 2.5 times the size of the Sun. One is around five times as luminous as the sun and the other around four times as luminous. The system is classified as a Beta Lyrae variable, he apparent magnitude ranging from 8.83 to 9.72 over 0.66 days.

It is a close binary system that consists of a white dwarf and another star, the former drawing off matter from the latter into a bright accretion disk. These systems are characterised by frequent eruptions and less frequent supereruptions. The former are smooth, while the latter exhibit short "superhumps" of heightened activity. One of the brightest dwarf novae in the sky, it has a baseline magnitude of 14.4 and can brighten to magnitude 8.4 during peak activity.

In 1961, Italian astrophysicist Margherita Hack proposed the secondary was a hot star surrounded by a shell of material, which was responsible for the eclipse, after observing it though the 1955-57 eclipse. Astronomer Su-Shu Huang published a paper in 1965 that outlined the defects of the Kuiper-Struve-Strömgren model, and proposed that the companion is a large disk system, edge-on from the perspective of Earth. Robert Wilson, in 1971, proposed that a "central opening" lay in the disk, a possible reason for the system's sudden brightening midway through the eclipse. In 2005, the system was observed in the ultraviolet by the Far Ultraviolet Spectroscopic Explorer (FUSE); as the star system was not emitting energy at rates characteristic of objects such as the neutron star binary system Circinus X-1 or black hole binary system Cygnus X-1, the object occupying the center of the disk is not expected to be anything of the sort; in contrast, a new hypothesis has suggested that the central object is actually a B5-type star.

Radial velocities taken of the primary as part of an extrasolar planet search show a linear trend in the velocities which is likely due to the secondary star. The pair can be resolved even through smaller telescopes. The binary system contains some of the closest young solar-type stars to the Sun, with a system age of about 200 million years old. The primary star (A) has been identified as a candidate for possessing a Kuiper-like belt, based on infrared observations.

This experience stands at the core of his first book, In the Sphere of Silence. In 1985 he returned to the UK where he learned about binary system marketing, and obtained professional qualification from CIMA (Chartered Institute of Management Accountants). In 1986 he traveled to the US where he obtained an MBA from the Southern Illinois University in 1986. At this time he was involved in multilevel marketing (MLM) on a part-time basis while working for Systematics, a subsidiary of IBM.

It is classified a blue-white B-type giant star and has an apparent magnitude of +4.35. (The individual components are classified as B6IV and B8.) The binary system has an orbital period of 14.1683 days. The binary's companion, Epsilon Volantis B, is 6.05 arcseconds away and has an apparent magnitude of +8.1. It too is a spectroscopic binary, consisting of two A-type main sequence stars with stellar classifications of A2 V and an orbital period of "a few days".

14 Persei is a binary starMaksym Yu. Pyatnytskyy and Ivan L. Andronov, “Reflection Effect in the Binary System 14 Persei with a Highly Eccentric Orbit”, RNAAS 4:24, 2020. in the northern constellation Perseus, located roughly 1,900 light years away from the Sun. It is visible to the naked eye as a faint, yellow-hued star with an apparent visual magnitude is 5.43. The object is slowly moving closer to the Earth with a heliocentric radial velocity of −1.2 km/s.

On 7 November 2006, the first stellar occultation by the satellite of an asteroid (Linus) was successfully observed by a group of Japanese observers according to a prediction that was made just one day before by Berthier et al. based on more than 5 years of regular observations of Kalliope binary system using adaptive optics systems on ground-based telescopes. The observed chords of Linus give a unique opportunity to estimate the size of the moonlet which was estimated to 20–28 km.

This system was found to have a variable radial velocity by Leah Allen and Adelaide Hobe of Lick Observatory in 1911. It was identified as a single-lined spectroscopic binary, and the orbital elements were published by Canadian astronomer W. E. Harper in 1926. The pair have an orbital period of 72.93 days and an eccentricity of 0.27. This is a RS Canum Venaticorum variable, indicating a close binary system with active star spots, and has the variable star designation BC Psc.

Rather than being an intrinsically variable star, it is an eclipsing binary. Other notable star systems in Perseus include X Persei, a binary system containing a neutron star, and GK Persei, a nova that peaked at magnitude 0.2 in 1901. The Double Cluster, comprising two open clusters quite near each other in the sky, was known to the ancient Chinese. The constellation gives its name to the Perseus cluster (Abell 426), a massive galaxy cluster located 250 million light-years from Earth.

Becker and Dehlinger had already predicted a negative diffusivity inside the spinodal region of a binary system. But their treatments could not account for the growth of a modulation of a particular wavelength, such as was observed in the Cu-Ni-Fe alloy. In fact, any model based on Fick's law yields a physically unacceptable solution when the diffusion coefficient is negative. The first explanation of the periodicity was given by Mats Hillert in his 1955 Doctoral Dissertation at MIT.

The smaller star is of spectral type F2V with a surface temperature of around 6750 K, and has around , , and between 4 and . Near Nusakan is Theta Coronae Borealis, a binary system that shines with a combined magnitude of 4.13 located 380±20 light-years distant. The brighter component, Theta Coronae Borealis A, is a blue-white star that spins extremely rapidly—at a rate of around 393 km per second. A Be star, it is surrounded by a debris disk.

They gave a revised rotation period for the primary of 3.7814 to 3.7824 hours with a brightness variation between 0.10 and 0.20 magnitude (). These observations also confirmed that Johnson is a binary system, giving a concurring orbital period of 21.78 to 21.797 hours for the satellite. For an asteroid of its size, Johnson has a somewhat fast spin rate, but still significantly above those of fast rotators. CALL adopts a rotation period of 3.7824 hours with an amplitude of 0.20 magnitude.

During the photometric observations in 2007, it was also revealed that Duponta is a synchronous binary asteroid with a minor-planet moon orbiting it every 17.57(8) hours. Based on mutual eclipse and occultation events with a magnitude between 0.06 and 0.12, the binary system has a mean-diameter ratio of , which translates into a diameter of 1.77 kilometers for the satellite. The minor planet moon has received the provisional designation . It has an estimated semi-major axis of 14 kilometers.

The 2012-photometric lightcurve observation also revealed, that Leakey is a synchronous binary asteroid with a minor-planet moon orbiting it every 50.24 hours. The moon (secondary) was designated . It is likely that the secondary body is tidally locked, which means that its rotation is synchronous with its orbital period. Based on only two observations at the Palmer Divide Observatory (), it is tentatively estimated that the size-ratio of the binary system is , which would give a 1-kilometer diameter for the satellite.

', provisional designation , is a bright asteroid and synchronous binary system on a highly eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately in diameter. It was discovered on 18 December 2003, by astronomers with the Catalina Sky Survey at the Catalina Station near Tucson, Arizona, in the United States. The V-type asteroid has a short rotation period of 2.3 hours. Its 210-meter sized minor-planet moon was discovered at Arecibo Observatory in May 2004.

Light from the Sun takes 5.5 hours to reach Pluto at its average distance (39.5 AU). Pluto has five known moons: Charon (the largest, with a diameter just over half that of Pluto), Styx, Nix, Kerberos, and Hydra. Pluto and Charon are sometimes considered a binary system because the barycenter of their orbits does not lie within either body. The New Horizons spacecraft performed a flyby of Pluto on July 14, 2015, becoming the first and, to date, only spacecraft to do so.

After the Spanish conquest of Peru by Francisco Pizarro, colonial officials burned the records kept by the Inca. There is currently a theory put forward by Gary Urton that the Quipus could have been a binary system capable of recording phonological or logographic data. Still, to date, all that is known is based on what was recorded by priests, from the iconography on Inca pottery and architecture, and from the myths and legends that have survived among the native peoples of the Andes.

Quantum computing is an area of research that brings together the disciplines of computer science, information theory, and quantum physics. The idea of information being a basic part of physics is relatively new, but there seems to be a strong tie between information theory and quantum mechanics. Whereas traditional computing operates on a binary system of ones and zeros, quantum computing uses qubits. Qubits are capable of being in a superposition, which means that they are in both states, one and zero, simultaneously.

Artist's conception of the surface of Proxima Centauri b. The Alpha Centauri binary system can be seen in the background, to the upper right of Proxima. The habitability of Proxima Centauri b has not been established, but the planet is subject to stellar wind pressures of more than 2,000 times those experienced by Earth from the solar wind. This radiation and the stellar winds would likely blow any atmosphere away, leaving the subsurface as the only potentially habitable location on that planet.

18 Vulpeculae is a binary star system in the northern constellation of Vulpecula, located about 489 light years away from the Sun. It is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of 5.51. The system is moving closer to the Earth with a heliocentric radial velocity of −11.7 km/s. This is a double-lined spectroscopic binary system with an orbital period of 9.3 days and a small eccentricity of 0.0116.

NGC 129 contains several giant stars. The brightest member of the cluster in DL Cassiopeiae, a binary system which contains a Cepheid variable with 8,00 days period. Using the fluctuations of the brightness of DL Cassiopeia from 8,7 to 9,28, Gieren and al in 1994 determined the distance of NGC 129 at 2034 ±110 kpc (6.630 ±360 ly), quite larger than the distance obtained by Turner et al. (1992), who obtained distance of 1,670 ±13 pc, from ZAMS fitting of the cluster.

Supernova type by initial mass and metallicity A model has been developed to show the evolution of a binary system leading to the currently observed state of AB7. The initial state has an primary and secondary in an orbit about twice its current size. The more massive primary leaves the main sequence after approximately 3.3 million years and overflows its roche lobe. In around 30,000 years it loses , only a small proportion of which is accreted by the secondary star.

HD 1237 is a binary star system approximately 57 light-years away in the constellation of Hydrus (the Water Snake). The visible star in the system, A, is considered to be a solar analog due close mass to the sun. HD 1237 differs from the sun in that HD 1237 is much younger, has high metallicity, has much cooler temperature and is in a binary system. As of 2000, it has been confirmed that an extrasolar planet orbits the star.

The inner pair of stars in this system form a spectroscopic binary with a combined magnitude of 5.44 and an orbital period of 1.302 days. The primary component is a giant star with a stellar classification of B8 III. Because the orbital plane is inclined near the line of sight, two form an eclipsing binary system. The eclipse of the primary component causes a 0.04 drop in magnitude, while the eclipse of the secondary results in a decrease of 0.03.

Zeta Eridani is a single-lined spectroscopic binary system with an orbital period of 17.9 days and an eccentricity of 0.14. The primary is a mild Am star with a stellar classification of kA4hA9mA9V. This notation indicates this is a main-sequence star with the Ca-II K absorption line strength (k) of an A4 star, and the hydrogen lines (h) and metallic lines (m) of an A9 star. It has about 185% of the Sun's mass and 10.3 times the Sun's radius.

Beta Scuti is the second brightest at magnitude 4.22, followed by Delta Scuti at magnitude 4.72. Beta Scuti is a binary system, with the primary with a spectral type similar to the Sun, although it is 1,270 times brighter. Delta Scuti is a bluish white giant star, which is now coming at the direction of the Solar System. Within 1.3 million years it will come as close to 10 light years from Earth, and will be much brighter than Sirius by that time.

In 2010, thermal flux from Sila–Nunam in the far-infrared was measured by the Herschel Space Telescope. As a result, its size, while it was assumed to be a single body, was estimated to lie within the range . Now that it is known to be a binary system, one body 95% the size of the other, the diameters are estimated to be . Sila–Nunam is very red in visible light and has a flat featureless spectrum in the near- infrared.

2759 Idomeneus is a dark Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 14 April 1980, by American astronomer Edward Bowell at the Anderson Mesa Station near Flagstaff, Arizona, in the United States, and later named after Idomeneus from Greek mythology. The D-type asteroid from the Jovian background population belongs to the 80 largest Jupiter trojans. It is a suspected binary system and potentially a slow rotator with a rotation period of 479 hours.

This is a close binary system with an orbital period of 2.6 days and an orbital plane that is oriented nearly face-on. It may be considered an Algol-type semidetached binary. The hotter primary component has a stellar classification of F2 IV, indicating it is an evolving subgiant star that is leaving the main sequence after consuming the hydrogen at its core. HR 5110 is classified as a RS Canum Venaticorum variable system, primarily due to chromospheric activity in the secondary component.

Based on its apparent brightness and assumed albedo, the estimated combined size of the Varda–Ilmarë system is , with the size of the primary estimated at . The total mass of the binary system is approximately . The density of both the primary and the satellite is estimated at about assuming that they have equal density. On the other hand, if the density or albedo of the satellite is lower than that of primary then the density of Varda will be higher up to .

A recent dynamical study points to Zeta Puppis originating in the Trumpler 10 OB association at around 300pc, but this is also a much older cluster and physical models still lead to a distance of 450-600pc. Zeta Puppis shows a high space velocity and very high rotation rate, and it has been speculated that it is a runaway star resulting from a supernova in a binary system, possibly the progenitor of the Gum Nebula but evidence supporting this is sparse.

Nu Andromedae is the prominent blue star in the upper right of this image. At the center is the Andromeda Galaxy Nu Andromedae is spectroscopic binary system with a nearly circular orbit that has a period of 4.2828 days. The primary component is a B-type main sequence star with a stellar classification of B5 V. The fainter secondary has a classification of F8 V, which makes it an F-type main sequence star. The pair is about 63 million years old.

8306 Shoko, provisional designation , is a Florian asteroid and a synchronous binary system from the inner regions of the asteroid belt, approximately in diameter. It was discovered on 24 February 1995, by Japanese astronomer Akimasa Nakamura at the Kuma Kogen Astronomical Observatory in southern Japan, who named it after Japanese singer-songwriter Shoko Sawada. The likely S-type asteroid has a rotation period of 3.35 hours. The discovery of its 1.3-kilometer minor-planet moon was announced in December 2013.

After being already recognized as an asteroid pair, American astronomer Brian Warner observed faint mutual eclipsing and occultation events in April 2013. After repeated lightcurve subtraction, he was able to show that Wasserburg is likely a binary system with a minor-planet moon orbiting it every 15.97 hours. Assuming a depth of 0.03 magnitude, he estimated a secondary-to-primary mean-diameter ratio of . The Johnston's archive derives a diameter of meters for the satellite, based on the primary diameter given by WISE.

In March 1984, the first but poorly rated rotational lightcurve of Summa was obtained from photometric observations by American astronomer Richard Binzel. It gave a rotation period of 9.66 hours with a brightness amplitude of 0.14 magnitude (). In August 2012, a refined yet ambiguous lightcurve with a period of 6.855 hours and an amplitude of 0.13 was obtained by Larry E. Owings at the Barnes Ridge Observatory in California (). Lightcurve analysis also considered that Summa might be a binary system.

DM Lyrae (DM Lyr for short) is a dwarf nova in the constellation Lyra. This binary system is composed of a primary star of unknown type, and a white dwarf companion. It erupted in 1928 and 1996 and reached about magnitude 13. Due to its position, coverage of the star by major northern hemisphere observatories is difficult during the winter months and very difficult by major southern hemisphere observatories all year round; it is quite possible that several outbursts have been missed.

Referencing contemporary Western views on gender diversity, psychologist Diane Ehrensaft stated: "I am witnessing a shake-up in the mental health community as training sessions, workshops and conferences are proliferating all over this country and around the world, demanding that we reevaluate the binary system of gender, throw out the idea that gender nonconformity is a disorder, and establish new guidelines for facilitating the healthy development of gender-creative children."Ehrensaft, D. (2011). "Gender Born, Gender Made". New York, NY: The Experiment.

The orbit has decayed since the binary system was initially discovered, in precise agreement with the loss of energy due to gravitational waves described by Albert Einstein's general theory of relativity. The ratio of observed to predicted rate of orbital decay is calculated to be 0.997±0.002. The total power of the gravitational waves emitted by this system presently is calculated to be 7.35 × 1024 watts. For comparison, this is 1.9% of the power radiated in light by the Sun.

3352 McAuliffe (), provisional designation , is a rare-type asteroid and suspected binary system, classified as near-Earth object of the Amor group, approximately 2 kilometers in diameter. It was discovered on 6 February 1981, by American astronomer Norman Thomas at Lowell's Anderson Mesa Station near Flagstaff, Arizona, United States. Originally, this asteroid was the target of the 1998 Deep Space 1 mission, but that mission was eventually rerouted to 9969 Braille. It was named in memory of Challenger crew member Christa McAuliffe.

In mathematics and digital electronics, a binary number is a number expressed in the base-2 numeral system or binary numeral system, which uses only two symbols: typically "0" (zero) and "1" (one). The base-2 numeral system is a positional notation with a radix of 2. Each digit is referred to as a bit. Because of its straightforward implementation in digital electronic circuitry using logic gates, the binary system is used by almost all modern computers and computer-based devices.

At least 1 in 18 stars brighter than 9.0 magnitude in the northern half of the sky are known to be double stars visible with a telescope.The Binary Stars, Robert Grant Aitken, New York: Dover, 1964, p. 260. The unrelated categories of optical doubles and true binaries are lumped together for historical and practical reasons. When Mizar was found to be a binary, it was quite difficult to determine whether a double star was a binary system or only an optical double.

The inner pair form a double-lined spectroscopic binary system with an orbital period of 3.26 days and an eccentricity of 0.13. Both stars appear to be similar B-type main-sequence stars with stellar classifications of B4 V. The third component has an angular separation of 22.8 arc seconds from the inner pair, and most likely is a smaller B-type main sequence star of spectral type B9V. The system is relatively young, with an estimated age of around 50 million years.

Spectroscopic parallax is another commonly used method for determining the distance to a binary system. No parallax is measured, the word is simply used to place emphasis on the fact that the distance is being estimated. In this method, the luminosity of a star is estimated from its spectrum. It is important to note that the spectra from distant stars of a given type are assumed to be the same as the spectra of nearby stars of the same type.

The star has a relatively high proper motion, traversing the celestial sphere at a rate of per year. The stellar classification of 68 Draconis is F5 V, indicating that it is a main sequence star that is fusing hydrogen into helium at its core to generate energy. The star appears to be over-luminous for a member of its class, being 0.73 magnitudes brighter than expected. This may indicate that this is a binary system with an unresolved secondary component.

CM Draconis (GJ 630.1A) is an eclipsing binary system approximately 47 light- years away in the constellation of Draco (the Dragon). The system consists of two nearly identical red dwarf stars located in the constellation Draco. The two stars orbit each other with a period of 1.27 days with a separation of 2.7 million kilometres (0.018 AU). Along with two stars in the triple system KOI 126, the stars in CM Draconis are the lightest stars with precisely measured masses and radii.

The system is most commonly referred to as UZ Fornacis, which is its variable star designation. The General Catalogue of Variable Stars describes it as "E+XM", meaning it is an eclipsing binary system consisting of a low-mass star with an X-ray-emitting companion. In the past the system has also been referred to using the designation EXO 033319–2554.2, which refers to its coordinates on the celestial sphere, as well as the EXOSAT satellite that detected it.

LS 5039 is a binary system in the constellation of Scutum. It has an apparent magnitude of 11.27, and it is about 8,200 light-years away. LS 5039 consists of a massive O-type main-sequence star, and a compact object (likely a black hole) that emits HE (high energy) and VHE (very high energy) gamma rays. It is one of the only three known star systems of this kind, together with LS I +61 303 and PSR B1259-63.

The binary system described above has an optical visual companion, discovered by William Herschel on July 21, 1781.See p.140, entry 32 in Designated as ADS 94 B in the Aitken Double Star Catalogue, it is a G-type star with an apparent visual magnitude of approximately 10.8. Although by coincidence it appears near to the other two stars in the sky, it's much more distant from Earth; the parallax observed by Gaia place this star more than 1,300 light years away.

Based upon proper motion variation, this is an astrometric binary system with high likelihood (99.8%). The visible component has a stellar classification of F0 Vn, indicating it is a F-type main-sequence star with "nebulous" lines due to rapid rotation. It is a Delta Scuti variable star with a period of 0.0960 days and an amplitude of 0.020 in magnitude. With 2.4 times the mass of the Sun it is spinning with a high projected rotational velocity of 133 km/s.

41 Tauri is the Flamsteed designation for a single-lined spectroscopic binary system in the zodiacal constellation of Taurus. The star has a visual magnitude of 5.19, making it visible to the naked eye from brighter suburban skies (according to the Bortle scale). Parallax measurements with the Hipparcos spacecraft put it at a distance of roughly from the Sun. This is a chemically peculiar star and was first classified as a silicon star by American astronomer William Morgan in 1933.

According to Fuhrmann and Chini (2015) this is an astrometric binary system, although Eggleton and Tokovinin (2008) deemed it to be a single star. The visible component is an ordinary F-type main-sequence star with a stellar classification of F5V. It is around 1.6 billion years old with 1.25 times the mass of the Sun and 1.40 times the Sun's radius. The star is radiating three times the luminosity of the Sun from its photosphere at an effective temperature of 6,395 K.

This star shows periodic radial velocity variations that can be best explained as a spectroscopic binary system. The visible component is an A-type main sequence star with a stellar classification of A3 V. It has twice the mass of the Sun and shines with about 12 times the Sun's luminosity from its outer atmosphere at an effective temperature of 9,206 K. The star is an estimated 237 million years old and is spinning with a projected rotational velocity of 78 km/s.

', provisional designation ', is a stony near-Earth object and potentially hazardous asteroid of the Apollo group, approximately in diameter. It was discovered on 27 December 2014 by the Catalina Sky Survey at the Catalina Station in Arizona, United States. In March 2015, a minor-planet moon, less than half the size of its primary, was discovered by radar astronomers at Goldstone Observatory. The primary body of the binary system has a rotation period of 3.3 hours, while the secondary's orbital period remains unknown.

X1822–371, associated with the optically visible star V691 Coronae Australis (abbreviated V691 CrA), is a neutron-star X-ray binary system at a distance of approximately 2-2.5 kiloparsecs. It is known to have a high inclination of i = 82.5°± 1.5°. This source displays relatively high brightness in the optical wavelengths when compared to the X-ray, making it a prototypical Accretion Disk Coronae (ADC) source, i.e. a source with a corona extending above and below its accretion disk.

Parallax measurements yield a distance estimate of around 730 light years from the Sun. The system is moving further away from the Earth with a heliocentric radial velocity of +18.7 km/s. This is a double-lined spectroscopic binary system with an orbital period of 260 days and an eccentricity of 0.024. The spectrum reveals the pair to consist of an A-type main-sequence star with a stellar classification of A1 V, and a red giant with a class of M6III.

It shows itself to be composed of a yellow and a white star when seen though a 7.5 cm telescope. This is a double-lined spectroscopic binary system with an orbital period of 39.88 days and an eccentricity of 0.25. The brighter member, component A, is yellow-white hued F-type subgiant star and a Gamma Doradus type variable, pulsating by 0.12 magnitudes with a dominant period of 1.45 days. There a magnitude 9.42 visual companion, located 16.2 arcseconds away.

As no terrestrial source of gravitational wave is powerful enough to produce a detectable signal, Virgo must observe the Universe. The more sensitive the detector, the further it can see gravitational waves, which then increases the number of potential sources. This is relevant as the violent phenomena Virgo is potentially sensitive to (coalescence of a compact binary system, neutron stars or black holes; supernova explosion; etc.) are rare: the more galaxies Virgo is surveying, the larger the probability of a detection.

Typical configuration of circumbinary planetary systems (not to scale), in which A and B are the primary and secondary star, while ABb denotes the circumbinary planet. giant planet orbiting the binary system PSR B1620-26, which contains a pulsar and a white dwarf star and is located in the globular cluster M4. A circumbinary planet is a planet that orbits two stars instead of one. Planets in stable orbits around one of the two stars in a binary are known.

Real mass transfer variations may be occurring in V Sge similar to SSXS RX J0513.9-6951 as revealed by analysis of the activity of the SSXS V Sge where episodes of long low states occur in a cycle of ~400 days. RX J0648.0-4418 is an X-ray pulsator in the Crab nebula. HD 49798 is a subdwarf star that forms a binary system with RX J0648.0-4418. The subdwarf star is a bright object in the optical and UV bands.

Based upon an annual parallax shift of 11.67 mas as seen from Earth, it is located about 280 light years from the Sun. It is moving away from the Sun, having a radial velocity of +26 km/s. This is a single-lined spectroscopic binary system with an orbital period of 4.6 years and an eccentricity of around 0.18. The spectroscopic binary nature of this star was discovered in 1901 by William Wallace Campbell using the Mills spectrograph at the Lick Observatory.

A close binary star system occurs when two stars orbit each other with an average separation that is of the same order of magnitude as their diameters. At these distances, more complex interactions can occur, such as tidal effects, transfer of mass and even collisions. Tidal interactions in a close binary system can result in modification of the orbital and rotational parameters. The total angular momentum of the system is conserved, but the angular momentum can be transferred between the orbital periods and the rotation rates.

Epsilon Persei (ε Persei, ε Per) is a multiple star system in the northern constellation of Perseus. It has a combined apparent visual magnitude of +2.88, which is bright enough to be viewed with the naked eye. Based upon parallax measurements, this system is located at a distance of roughly 640 light-years (196 parsecs) from Earth. This is a spectroscopic binary system, which means that the presence of an orbiting companion has been revealed by radial velocity variations in the spectrum of the primary.

FF Aql is a possible quadruple star system. Analysis of its spectrum shows that it is a spectroscopic binary system with the fainter companion calculated to be a main sequence star of spectral type A9V to F3V, orbiting every 3.92 years. A third star, revealed by speckle interferometry, is likely to be a cooler star that has evolved off the main sequence. A fourth star, that is of magnitude 11.4 and located 6 arcseconds away, is unlikely to be a member of the system.

The Louisiana free people of color were often literate and educated, with a significant number owning businesses, properties, and even slaves. Although Code Noir forbade interracial marriages, interracial unions were widespread under the system known as plaçage. The mixed-race offspring (creoles of color) from these unions were among those in the intermediate social caste of free people of color. The English colonies, in contrast, insisted on a binary system that treated mulatto and black slaves equally under the law, and discriminated against equally if free.

About 4° to the north of Gamma Persei is the radiance point for the annual Perseid meteor shower. This is a wide eclipsing binary system with an orbital period of 5,329.8 days (14.6 years). This eclipse was first observed in 1990 and lasted for two weeks. During an eclipse, the primary passes in front of the secondary, causing the magnitude of the system to decrease by 0.55. The primary component of this system is a giant star with a stellar classification of G9 III.

Being part of a binary system, Manwë has one known companion named Thorondor, formally designated (385446) Manwë I Thorondor. It is estimated to be about two-thirds the size of the primary, approximately for a volume equivalent diameter. The rotation period of Thorondor is uncertain, though a best-fit model suggests a very slow rotation period of 309.3 days. Thorondor's rotation is expected to be chaotic like Pluto's smaller moons, as a result of gravitational torquing by Manwë over the course of their eccentric mutual orbit.

Dimorphos is a small asteroid satellite that was discovered in 2003. It is the minor-planet moon of a synchronous binary system with 65803 Didymos as the primary asteroid. After being provisionally designated as S/2003 (65803) 1 with informal nicknames such as "Didymos B" and "Didymoon", the Working Group Small Body Nomenclature (WGSBN) of the International Astronomical Union gave the satellite its official name on 23 June 2020. At a diameter of , it is one of the smallest astronomical objects to have a permanent name.

The upper panel shows the full light curve. The second panel is a blow-up where tiny secondary minima are visible (their depth is 1% of the deeper minimum). The third panel shows the projection on the plane of the sky (i.e. as we see the system) at different phases. From Carla Maceroni and the CoRoT binary team # HD 174884: Tidally induced pulsations have been detected in the high eccentricity (e=0.29) and short period binary system HD 174884 consisting of two B stars.

One model for the formation of this category of supernova is a close binary star system. The progenitor binary system consists of main sequence stars, with the primary possessing more mass than the secondary. Being greater in mass, the primary is the first of the pair to evolve onto the asymptotic giant branch, where the star's envelope expands considerably. If the two stars share a common envelope then the system can lose significant amounts of mass, reducing the angular momentum, orbital radius and period.

Gliese 676 is a 10th-magnitude wide binary system of red dwarfs that has an estimated minimum separation of 800 AU with an orbital period of greater than 20,000 years. It is located approximately 54 light years away in the constellation Ara. In 2009, a gas giant was found in orbit around the primary star, in addition to its confirmation in 2011 there was also a strong indication of a companion; the second gas giant was characterised in 2012, along with two much smaller planets.

This is a single-lined spectroscopic binary system with an orbital period of and an eccentricity of 0.13. The a sin i value is , where a is the semimajor axis and i is the orbital inclination to the line of sight from the Earth. The system is a source for X-ray and far-UV emission, with the latter most likely coming from the companion. The primary component is an aging red giant star on the asymptotic giant branch with a stellar classification of M4.5 III.

A white dwarf star in a close binary system can accumulate material from its companion until it ignites and blows off in a thermonuclear explosion, known as a nova. These stars generally brighten by 7 to 16 magnitudes. Nova Circini 1926, also known as X Circini, was observed at magnitude 6.5 on 3 September 1926, before fading and fluctuating between magnitudes 11.7 and 12.5, during 1928, and magnitude 13, in 1929. Nova Circini 1995 (BY Circini) reached a maximum apparent magnitude of 7.2 in January 1995.

Both members of the LH54-425 binary system are hot, massive, and luminous stars. The less massive secondary has an effective surface temperature of 41,000 K and the more massive primary is 45,000 K. The stars are 8 and 11 times the size of the sun, and the combination of high temperature and large size means the primary star is 500,000 times as luminous as the sun and the secondary 160,000 times as luminous. They are emitting a stellar wind with a velocity of 2,800 km/s.

The binary system has a period of 790 years and is 73 light-years from Earth. The primary and secondary, both white stars, are of magnitude 4.8 and 6.2, respectively. The unrelated tertiary component is of magnitude 6.9. Though the tertiary component is visible in binoculars, the primary and secondary currently require a medium-sized amateur telescope to split, as they will through the year 2020. The two stars will be closest between 2043 and 2050, when they will require a telescope with larger aperture to split.

Iota Crateris (ι Crateris) is the Bayer designation for a binary star system in the southern constellation of Crater. It is faintly visible to the naked eye with an apparent visual magnitude of 5.48. According to the Bortle scale, this means it can be viewed from suburban skies at night. Based upon an annual parallax shift of 37.41 mas, Iota Crateris is located 87 light years from the Sun. This is an astrometric binary system with an estimated orbital period of roughly 79,000 years.

Quipucamayocs (Quechua khipu kamayuq "khipu specialist", plural: khipu kamayuqkuna) could be summoned to court, where their bookkeeping was recognised as valid documentation of past payments. Some of the knots, as well as other features, such as color, are thought to represent non-numeric information, which has not been deciphered. It is generally thought that the system did not include phonetic symbols analogous to letters of the alphabet. However Gary Urton has suggested that the quipus used a binary system which could record phonological or logographic data.

At the center of the cluster lies DH Cephei, a close, double- lined spectroscopic binary system consisting of two massive O-type stars. This pair are the primary ionizing source for the surrounding H II region, and are driving out the surrounding gas and dust while triggering star formation in the neighboring region. Of the variable stars that have been identified in the cluster, 14 have been identified as pre-main sequence stars while 17 are main sequence stars that are primarily B-type variables.

Iota1 Cygni, Latinized from ι1 Cygni, is a probable binary star system in the northern constellation Cygnus, and is separated by less than a degree from its brighter visual neighbor, Iota2 Cygni. It is near the lower limit of visibility to the naked eye with an apparent visual magnitude of 5.75. The system is located approximately 387 light years away based on parallax, and it is drifting further away with a radial velocity of +2 km/s. This is a candidate double-lined spectroscopic binary system.

Normally one would expect to see evidence of hydrogen and helium, but when these supernova occur in a binary system the companion has sometimes gravitationally stripped the outer layers of the progenitor star away, leaving only the heavier elements. Type Ib supernovae have no hydrogen, while Type Ics have neither hydrogen or helium. Over the following weeks Alexei Filippenko et al. and the University of California at Berkeley discovered prominent He I absorption lines, thus changing the classification of the supernova to Type Ib.

The outer pair has an orbital period of 1,598 years with an eccentricity of 0.536. The magnitude 6.02 primary, component A, is itself a binary system consisting of two stars of similar mass, roughly 1.5 times the mass of the Sun each, with an orbital period of . It has a stellar classification of F5 V, matching an F-type main-sequence star. As of 2017, component B is a magnitude 9.50 star at an angular separation of from the primary along a position angle of 285°.

It is advancing closer to the Earth with a heliocentric radial velocity of −122.7 km/s, and may come as close as in around 643,000 years. This appears to be a single-lined spectroscopic binary system with an orbital period of 130.7 days and an eccentricity of 0.366. It has an "a sin i" value of , where a is the semimajor axis and i is the inclination to the line of sight from the Earth. This value provides a lower bound on the actual semimajor axis.

This means it is located at a distance of approximately from Earth, give or take a 3 light-year margin of error. This is a single-lined spectroscopic binary system, meaning that the presence of an orbiting companion is revealed through shifts in the spectrum of the primary star. The pair orbit each other with a period of 266.544 days at a high eccentricity of 0.833. Little is known about this companion, although its mass can be estimated as 140% of the mass of the Sun.

It is moving closer with a heliocentric radial velocity of −8 km/s. The primary component is an aging red giant star with a stellar classification of . The suffix notation indicates this is a mild barium star, which means the stellar atmosphere is enriched with s-process elements. It is either a member of a close binary system and has previously acquired these elements from a (now) white dwarf companion or else it is on the asymptotic giant branch and is generating the elements itself.

3 Boötis is a close binary star system in the northern constellation of Boötes, located 310 light years away from the Sun based upon parallax. It can be viewed with the naked eye in excellent seeing conditions as a dim star with an apparent visual magnitude of 5.97. The system is moving further from the Earth with a heliocentric radial velocity of 12 km/s. This is a double-lined spectroscopic binary system with an orbital period of 36 days and an eccentricity of 0.543.

This is a single-lined spectroscopic binary system, which means that the two stellar components have not been individually resolved with a telescope. Instead, their orbital motion can be tracked through periodic shifts in the spectrum of the primary. The gravitational perturbation of the hidden secondary component upon the primary is causing the latter to first move toward and then away from the Earth, creating Doppler shift changes in the spectrum. From these subtle shifts, the orbital elements of the pair can be extracted.

Kepler-47 is a binary star system located about away from Earth. The binary system is composed of a G-type main sequence star (Kepler-47A) and a red dwarf star (Kepler-47B). The stars orbit each other around their barycenter, or center of mass between them, completing one full orbit every 7.45 days. The stars orbit their barycenter from a distance of about 0.084 AU. The stars have 104% and 35% of the Sun's mass, and 96% and 35% of the Sun's radius, respectively.

While photons exist as excitations of a vector potential and so contain an oscillating dipole term, gravitons are a spin-2 field and so have an oscillating quadrupole term. For efficient lasing to occur, there are several conditions that must be met: # There must be particles in an excited state capable of emitting radiation at the desired frequency. In a normal laser, these would be valence electrons in an excited state. For a gaser, the more straightforward analog would be a binary system of massive bodies.

NGC 7332 is an edge-on peculiar lenticular galaxy located about 67 million light-years away. It possesses a (peanut shell)-shaped bulge, associated with stellar bar.Bogdan C. Ciambur; Alister W. Graham (2016), Quantifying the (X/peanut)-shaped structure in edge-on disc galaxies: length, strength, and nested peanuts NGC 7332 and NGC 7339 form a dynamically isolated binary system (number 570 in the catalog of double galaxies compiled by Igor Karachentsev), and are likely orbiting each other. NGC 7332 is the brighter of the two galaxies.

This is a double-lined spectroscopic binary system with an essentially circular orbit and a period of one week. The primary component is a chemically peculiar star of type CP1, or Am star, with a stellar classification of A8m. Abt and Morrell (1995) classed it as Am(A7/F0/F2), indicating it has the hydrogen lines of an A7 star, the calcium K line of a cooler F0 star, and the metallic kines of an F2 class. It has been mentioned as a potential variable star.

The brighter component, ζ Aquarii A (also called ζ2 Aquarii), is a yellow-white-hued F-type main sequence star with an apparent magnitude of +4.42. Its companion, ζ Aquarii B (also called ζ1 Aquarii), is a yellow-white-hued F-type subgiant with an apparent magnitude of +4.51. The fact that their brightness is so similar makes the pair easy to measure and resolve. Zeta Aquarii A is known to be an astrometric binary system, as it undergoes regular perturbations from its orbit.

The carbon stars have more carbon than oxygen in their atmospheres. In most stars, such as class M giants, the atmosphere is richer in oxygen than carbon and they are referred to as oxygen-rich stars. S-type stars are intermediate between carbon stars and normal giants. They can be grouped into two classes: intrinsic S stars, which owe their spectra to convection of fusion products and s-process elements to the surface; and extrinsic S stars, which are formed through mass transfer in a binary system.

During Brian Warner's photometric observations in 2013, it was revealed, that Suruga is a synchronous binary system with a minor-planet moon in orbit. The satellite has an orbital period of 16.386. Based on the brightness variations of the mutual eclipsing/occulation events, Warner estimates that the satellite's mean-diameter is at least 21% of that of Surugas (Ds/Dp of >). The Johnston's Archive derives a satellite diameter of 1.33 kilometer and estimates a semi-major axis of 11 kilometers for the moon's orbit.

GCIRS 13E is an infrared and radio object near the galactic centre. It is believed to be a cluster of hot massive stars, possibly containing an intermediate-mass black hole (IMBH) at its centre. GCIRS 13E was first identified as GCIRS 13, which was later resolved into two components GCIRS13E and W. GCIRS 13E was initially modelled as a single object, possibly a binary system. It was even classified as a Wolf-Rayet star because of its strong emission line spectrum, and named WR 101f.

The iron–iron carbide (Fe–Fe3C) phase diagram. The percentage of carbon present and the temperature define the phase of the iron carbon alloy and therefore its physical characteristics and mechanical properties. The percentage of carbon determines the type of the ferrous alloy: iron, steel or cast iron A phase diagram for a binary system displaying a eutectic point. One type of phase diagram plots temperature against the relative concentrations of two substances in a binary mixture called a binary phase diagram, as shown at right.

Her 1951 calculations of the orbit of the difficult astronomical binary star system Ross 614 were used to successfully find and image the system's secondary star. These calculations were used by Walter Baade to find and optically resolve this binary system for the first time using the then new Hale Telescope at the Palomar Observatory in California. She is listed as professor emerita of astronomy and director emerita of the Sproul Observatory in the 2010 Swarthmore college catalog. She last published astronomy research papers in 1983.

Orbits of the HR 6819 hierarchical triple star system: an inner binary with one star (orbit in blue) and a black hole (orbit in red), encircled by another star in a wider orbit (also in blue). In a physical triple star system, each star orbits the center of mass of the system. Usually, two of the stars form a close binary system, and the third orbits this pair at a distance much larger than that of the binary orbit. This arrangement is called hierarchical.

Zeta Ceti is a single-lined spectroscopic binary system with an orbital period of 4.5 years and an eccentricity of 0.59. The primary, Baten Kaitos, is an evolved K-type giant star with a stellar classification of . The suffix notation indicates this is a weak barium star, showing slightly stronger than normal lines of singly-ionized barium. This star has an estimated 2.34 times the mass of the Sun and, at an estimated age of 1.24 billion years, has expanded to 25 times the Sun's radius.

This is known to be a spectroscopic binary system, although there is no information about the secondary component. Based upon parallax measurements, this system is located at a distance of about from the Earth. The spectrum of the primary star matches a stellar classification of A9III, which indicates this is a giant star that has exhausted the hydrogen at its core and evolved away from the main sequence. The effective temperature is about 7,031 K, giving the star a white hue characteristic of A-type stars.

The satellite is 1.4 magnitudes dimmer than Huya (HV=5.04), giving a visual absolute magnitude of 6.44 for the satellite. The satellite is relatively large compared to Huya, being slightly larger than half the primary's diameter of . The size ratio of the satellite to the primary is 0.525. The large size ratio is analogous to the Pluto–Charon binary system, in which Pluto's large moon Charon is large and massive enough such that the center of mass (barycenter) is located in the space between Charon and Pluto.

23 Vulpeculae is a triple star system in the northern constellation of Vulpecula. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.52 and it is located approximately 340 light years away from the Sun based on parallax. The system is moving further from the Earth with a heliocentric radial velocity of +1.47 km/s. Component A forms a binary system with an orbital period of 25.33 years, an eccentricity of 0.40, and a semimajor axis of .

It is around double the size of and around 33 times as luminous as the sun and rotates rapidly. Like Beta, it is surrounded by a dusty debris disk, which has a radius 80 times the distance of the Earth from the Sun. Lying near Gamma and forming an optical triple system with it are Delta and 7 Trianguli. Delta is a spectroscopic binary system composed of two yellow main sequence stars of similar dimensions to the Sun that lies 35 light-years from Earth.

A transfer DNA (T-DNA) binary system is a pair of plasmids consisting of a T-DNA binary vector and a vir helper plasmid. The two plasmids are used together (thus binary"As I remember, the "binary" refers to the function of interest being divided into two parts encoded by two separate plasmids rather than two bacterial hosts: we used the term "shuttle vectors" to refer to the multiple host property." (P. R. Hirsch, personal communication to T. Toal, Feb 27, 2013)) to produce genetically modified plants.

It is thought that they are caused by an inhomogeneous distribution of metals in the atmospheres of these stars, so that the surface of the star varies in brightness from point to point.pp. 83–85, Variable Stars, Michel Petit, foreword by Paolo Maffei, tr. from French by W. J. Duffin, Chichester, UK: John Wiley & Sons, 1987, . The type-star which this class is named after is α² Canum Venaticorum, a star in the binary system of Cor Caroli, which is in the northern constellation of Canes Venatici.

Theta Ursae Majoris (Theta UMa, θ Ursae Majoris, θ UMa) is a suspected spectroscopic binary star system in the northern circumpolar constellation of Ursa Major. It has an apparent visual magnitude of 3.17, placing it among the brighter members of this constellation. The distance to this star has been measured directly using the parallax method, yielding an estimated value of . In 1976, this was reported as a spectroscopic binary system by Helmut A. Abt and Saul G. Levy, giving it an orbital period of 371 days.

Some who do not identify within a binary system experience being at the bottom of the hierarchy. The multitude of different variables such as race, ethnicity, age, gender, and more can lower or raise one's perceived power. Worldwide, there are many individuals and several subcultures that can be considered exceptions to the gender binary or specific transgender identities. In addition to individuals whose bodies are naturally intersex, there are also specific social roles that involve aspects of both or neither of the binary genders.

The HU Aquarii binary system exhibits variations in the timing of the eclipses. Schwarz et al. (2009) note that the variations are too large to be caused by the Applegate mechanism, and are within the expected range of magnetic braking but 30 times too large to be caused by gravitational radiation alone. As an alternative explanation, they suggested that the variations might be caused by an object in orbit around the binary, causing it to move back and forth along the line-of-sight to the system.

53 Camelopardalis is a binary star system in the northern circumpolar constellation of Camelopardalis, located 290 light years away from the Sun as determined by parallax measurements. It has the variable star designation AX Camelopardalis; 53 Camelopardalis is the Flamsteed designation. This object is dimly visible to the naked eye as a white hued star with a baseline apparent visual magnitude of +6.02. It is a single-lined spectroscopic binary system with an orbital period of 6.63 years and a high eccentricity of 0.718.

The system is moving closer to the Earth with a heliocentric radial velocity of −2 km/s. Abt et al. (1969) determined this to be a single-lined spectroscopic binary system and computed an orbital solution with a period of 80.17 days and an eccentricity of 0.35. However, what appeared to be an ellipticity effect with a period of was found, which was inconsistent with the computed orbit, and the lack of modulation of the amplitude did not fit with the large orbital eccentricity.

In a 2017 paper, Sarah Sadavoy and Steven Stahler argued that the Sun was likely part of a binary system at the time of its formation, leading them to suggest "there probably was a Nemesis, a long time ago". Such a star would have separated from this binary system over four billion years ago, meaning it could not be responsible for the more recent perceived cycle of mass extinctions, Douglas Vakoch told Business Insider, adding that "If the sun really was part of a binary star system in its early days, its early twin deserves a benign name like Companion, rather than the threatening Nemesis." More recent theories suggest that other forces, like close passage of other stars, or the angular effect of the galactic gravity plane working against the outer solar orbital plane (Shiva Hypothesis), may be the cause of orbital perturbations of some outer Solar System objects. In 2011, Coryn Bailer-Jones analyzed craters on the surface of the Earth and reached the conclusion that the earlier findings of simple periodic patterns (implying periodic comet showers dislodged by a hypothetical Nemesis star) were statistical artifacts, and found that the crater record shows no evidence for Nemesis.

Salvius, Stackholm. He adopted and popularized a binomial (or binary) system of designation (Morton, 1981) using one name as the genus and a second name as the species name both in Latin or Latinised. This specific name he referred to as a trivial name nomen triviale consisting of a single word, normally a Latin adjective, but any single word would suffice, to identify a particular species, but not intended to describe it. He developed a coherent system for naming organisms and divided the plant kingdom into 25 classes (according to Smith p.

Lightcurve observations in 2005 revealed that Lundia is a binary system of two similarly sized objects orbiting their common centre of gravity. "Lundia" now refers to one of the objects, the other being provisionally designated S/2005 (809) 1. The similarity of size between the two components is suspected because during mutual occultations the brightness drops by a similar amount independently of which component is hidden.Poznań observatory (Lightcurve showing signature of the binary) Due to the similar size of the primary and secondary the Minor Planet Center lists this as a binary companion.

A period of 5.1 days has been assigned for the orbit of the binary, which is approximately the same as the rotation period of the star. Unlike typical rotating ellipsoidal variables, there is no clearly defined period in the variations in brightness. Data derived from the assumption of a binary system, for example the mass, are highly uncertain due to the lack of information about the inclination or eccentricity of the orbit, or even whether there is a companion. The spectral lines of 68 Cygni vary erratically, but possibly with a period around 5 days.

The mass of the star is likely to be around 26 solar masses, according to a 2011 study by Ducati, Penteado, and Turcati. However, due to the uncertain nature of the binary system hypothesis, the true mass could be much different than this. If the star actually has a mass of 51 solar masses (the median mass reported by Hohle, Neuhäuser, and Schutz in 2010), the star's bolometric luminosity would be over 1 million solar luminosities, making it among the most luminous stars known, although data to support this mass is tenuous at best.

This star system was first catalogued as a binary star by William Herschel in the late 18th century in his study of binary stars. Herschel proved that this system is a gravitationally bound binary system where the two stars orbit around a common center of mass. This was an important contribution to the proof that Newton's law of universal gravitation applied to objects beyond the solar system. He commented at the time that there was a possible third unseen companion affecting the orbit of the two visible stars.

Kappa Velorum is a spectroscopic binary system consisting of a pair of stars that complete an orbit around each other with a period of 116.65 days and an eccentricity of 0.19. Because the individual stars have not been resolved, further details of the orbit have not yet been determined. The combined stellar classification of the pair is B2 IV, which matches the class of a B-type subgiant star that has exhausted the hydrogen at its core and begun to evolve into a giant. It has an estimated size of 6.9 times the Sun's radius.

But many free people of African descent were mixed race. When the U.S. took over Louisiana, Americans from the Protestant South entered the territory and began to impose their norms. They officially discouraged interracial relationships (although white men continued to have unions with black women, both enslaved and free.) The Americanization of Louisiana gradually resulted in a binary system of race, causing free people of color to lose status as they were grouped with the slaves. They lost certain rights as they became classified by American whites as officially "black".

Shape model of Didymos and its satellite Dimorphos, based on photometric lightcurve and radar data The primary body of binary system, Didymos, orbits the Sun at a distance of 1.0–2.3 AU once every 2 years and 1 month (770 days). The pathway of the orbit has an eccentricity of 0.38 and an inclination of 3° with respect to the ecliptic. It was known to be closest to Earth in November 2003 with a distance of 7.18 million km. It is expected to come around that near after 120 years.

The primary star pulsates with typical γ Dor frequencies and shows a period spacing consistent with high order g-modes of degree l=1. # HR 6902: The binary system ζ Aurigae HR 6902 containing a red giant and a B star was observed by CoRoT during two runs, which allowed us to fully cover the primary as well as the secondary eclipses. This system is presently being analyzed with the ultimate goal of bringing new constraints on the internal structure of the red giant in particular.Maceroni, C. et al.

Astronomers believe that supermassive black holes (SMBHs) can be ejected from the centers of galaxies by gravitational wave recoil. This happens when two SMBHs in a binary system coalesce, after losing energy in the form of gravitational waves. Because the gravitational waves are not emitted isotropically, some momentum is imparted to the coalescing black holes, and they feel a recoil, or "kick," at the moment of coalescence. Computer simulations suggest that the kick can be as large as 10^5 km/s, which exceeds escape velocity from the centres of even the most massive galaxies.

A series of photometric and spectroscopic observations carried out by P. Ostrov between from 1998 to 2001 revealed that LH54-425 varied very slightly with a regular period of 2.2475 days due to distorted stars in a close binary system composed by an O3 class giant and an approximately O5 class companion. The masses of the two stars were estimated at and . A derivation of the orbit in 2008 using more accurate radial velocity data defined the companions as O3 and O5 main sequence stars with masses of and respectively.

Lying 75±0.5 light-years from Earth, Alphecca is believed to be a member of the Ursa Major Moving Group of stars that have a common motion through space. Located 112±3 light-years away, Beta Coronae Borealis or Nusakan is a spectroscopic binary system whose two components are separated by 10 AU and orbit each other every 10.5 years. The brighter component is a rapidly oscillating Ap star, pulsating with a period of 16.2 minutes. Of spectral type A5V with a surface temperature of around 7980 K, it has around , 2.6 solar radii (), and .

65803 Didymos, provisional designation , is a sub-kilometer asteroid and synchronous binary system, classified as potentially hazardous asteroid and near-Earth object of both the Apollo and Amor group. The asteroid was discovered in 1996, by the Spacewatch survey at Kitt Peak, and its small 160-metre minor-planet moon was discovered in 2003, named Dimorphos. Due to its binary nature, it was then named "Didymos", the Greek word for twin. Didymos is the target of the proposed AIDA asteroid-mission to test the viability of asteroid impact avoidance by collision with a spacecraft.

During the photometric observations in 2006/7, it was revealed that Iwamoto ("primary") is a synchronous binary system with a minor-planet moon ("secondary") orbiting it every 4.917 days (or 118 hours, which identical to the primary's rotation). Based on the secondary-to-primary mean-diameter ratio (Ds/Dp) of at least 0.76, it was estimated that Iwamoto and its moon measure 4.0 and 3.5 kilometers, respectively. The diameter of Iwamoto has since increased to 5.5 kilometers (see above). The "Jonstonarchive" estimates that the moon has a semi-major axis of 31 kilometers.

This binary system is located in close proximity to the young star AU Microscopii, with a projected separation of . This indicates that the three may form a wide hierarchical triple system, with the AT Microscopii pair orbiting AU Microscopii over a period of 10 million years. All three stars are candidate members of the Beta Pictoris moving group, one of the nearest associations of stars that share a common motion through space. This group averages a distance of about from the Earth, but are scattered across a volume roughly in diameter.

200px PSR J0740+6620 is a neutron star in a binary system with a white dwarf, located 4,600 light years away. It was discovered in 2019, by astronomers using the Green Bank Telescope in West Virginia, U.S., and confirmed as a rapidly rotating millisecond pulsar. As of 2019, it is among the most massive neutron stars ever observed – with solar masses placing it near the boundary of the theoretical maximum. Its mass was calculated via the Shapiro delay of its white dwarf companion as it passed edge-on to Earth.

Rho Pegasi, Latinized from ρ Pegasi, is a star in the northern constellation of Pegasus, near the southern constellation boundary with Pisces. This is a probable astrometric binary system, as determined by changes to the proper motion of the visible component. It has a white hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.90. The system is located at a distance of approximately 274 light years from the Sun based on parallax, but it is drifting closer with a radial velocity of −10.6 km/s.

This companion has a mass estimated between 1.4 and 1.9 solar masses and is probably an unevolved main sequence star. The system must have interacted in the past when the primary was a red giant, which is likely related to the formation of disk. All RV Tauri stars with dust disks are believed to be part of a binary system. Slow periodic variations in the mean brightness of SX Centauri have been detected, leading the star to be classified as an RV Tauri star of the photometric class b (RVb).

It is actually a confirmed spectroscopic binary system with a high temperature subdwarf O-type companion in a 28-day orbital period. The latter is heating the nearest side of the circumstellar gaseous disk that surrounds the primary. Orbiting the primary pair is 59 Cyg Ab, a magnitude 7.64 A-type main-sequence star of class A3V, located at an angular separation of . A fourth component is a magnitude 9.8 A-type giant star of class A8III at a separation of along a position angle (PA) of 352°, as of 2008.

Several alternative processes for the production of extreme mass ratio inspirals are known. One possibility would be for the central supermassive black hole to capture a passing object that is not bound to it. However, the window where the object passes close enough to the central black hole to be captured, but far enough to avoid plunging directly into it is extremely small, making it unlikely that such event contribute significantly to the expected event rate. Another possibility is present if the compact object occurs in a bound binary system with another object.

Little is known of the secondary star except that its mass is around , deduced from the mass ratio of the binary system and the modelled mass of the primary star. The primary itself is calculated to have a mass of , but a luminosity of . It is slightly cooler than the sun, although this varies by over a thousand K as the star pulsates. The total system mass can be estimated from the dynamics of the disc, and this gives a value of , slightly lower than from other methods.

1139 Atami, provisional designation , is a stony asteroid and sizable Mars- crosser, as well as a synchronous binary system near the innermost region of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 1 December 1929, by Japanese astronomers Okuro Oikawa and Kazuo Kubokawa at the Tokyo Astronomical Observatory () near Tokyo. It was named after the Japanese city of Atami. It has the lowest Minimum orbit intersection distance (MOID) to Mars of any asteroid as large as it, its orbit intersecting only 0.03 astronomical units from the planet.

Radial velocity changes were detected corresponding to the brightness variations, but the idea that these were caused by stellar pulsations and temperature changes was largely dismissed in favour of orbital motions of a binary star. More accurate observations eventually proved beyond doubt that the brightness variations were caused by pulsations in the atmospheres of the stars, with the stars being smallest and hottest near maximum brightness. RT Aurigae has been suspected to be a spectroscopic binary system, but this has not been confirmed. The strongest evidence was found in 2013 using CHARA array optical interferometry.

The original Hipparcos parallax was given as , leading to a distance of being assumed in many texts. A distance of has been derived from fitting the spectrum. 26 Aurigae is a visual binary system, and the two stars orbit each other every 52.735 years with an ellipticity of 0.653 and an angular separation . The system is made of a magnitude 6.29 G-type red giant, and a hotter magnitude 6.21 star that has been classified as an early B-type main-sequence star to an A-type subgiant star.

This has been identified as a visual binary system with an orbital period of in a circular orbit (eccentricity of zero). The primary component has a stellar classification of A9/F0 V, matching a main sequence star with a spectrum showing mixed traits of an A/F-type. (Cowley and Fraquelli [1974] has previously assigned it a giant star class of A8 III.) It is a chemically peculiar Am star, showing metallic lines with no magnetic field. The star has 1.7 times the mass of the Sun and 2.1 times the Sun's radius.

The visible component is an aging giant star with a stellar classification of . The suffix notation indicates this is a mild barium star, which means the stellar atmosphere is enriched with s-process elements. It is either a member of a close binary system and has previously acquired these elements from a (now) white dwarf companion or else it is on the asymptotic giant branch and is generating the elements itself. 2 Aurigae is 1.80 billion years old with 2.86 times the mass of the Sun and has expanded to 48 times the Sun's radius.

The magnitude 5.08 primary member, designated component A, is a single-lined spectroscopic binary system in a circular orbit with a period of 3.7887 days. The visible member has a stellar classification of A9 IV or A V, depending on the source, and is a Delta Scuti variable with an amplitude of 0.08 magnitude and a period of 2.11 hours. It is 609 million years old with 1.64 times the mass of the Sun. Component B lies about to the north of the primary and is merely a visual companion.

The orbit of this binary system is slowly shrinking as it loses energy because of emission of gravitational radiation, causing its orbital period to speed up slightly. The rate of shrinkage can be precisely predicted from Einstein's General Theory of Relativity, and over a thirty-year period Taylor and his colleagues have made measurements that match this prediction to much better than one percent accuracy. This was the first confirmation of the existence of gravitational radiation. There are now scores of binary pulsars known, and independent measurements have confirmed Taylor's results.

39 Boötis is a triple star system located around 224 light years away from the Sun in the northern constellation of Boötes. It is visible to the naked eye as a faint, yellow-white hued star with a combined apparent magnitude of 5.68. The system is moving closer to the Earth with a heliocentric radial velocity of −31 km/s. The magnitude 6.36 primary, component A, is actually a double- lined spectroscopic binary system with an orbital period of 12.822 days, an eccentricity of 0.39, and an angular separation of .

Another great discovery from the double pulsar is the observation of an eclipse from a conjunction of the superior and weaker pulsar. This happens when the doughnut shaped magnetosphere of one pulsar, which is filled with absorbing plasma, blocks the companion pulsar's light. The blockage, lasting more than 30 s, is not complete, due to the orientation of the plane of rotation of the binary system relative to Earth and the limited size of the weaker pulsar's magnetosphere; some of the stronger pulsar's light can still be detected during the eclipse.

An image of HH 24 taken by the Hubble Space Telescope The image of HH 24 taken by the Hubble Space Telescope is probably the most well known image of this Herbig-Haro object. HH 24 resembles a lightsaber from the science fiction movies Star Wars and the Hubble image was published during the release of Star Wars Episode VII: The Force Awakens. HH 24 contains a class 0 protostar, which might be a proto-binary system. The disks around these objects are highly misaligned, which is a sign of turbulent fragmentation.

After evoking the spirits with the iroke Ifá, the babalowo then throws the opele; each of the eight half-nuts will land concave up or concave down, heads or tails. A single line represents "heads" while two vertical lines symbolize "tails" – this process is recorded in the iyerosun powder, as it is done with the palm nuts. Thus, this binary system of one and two vertical lines gives rise to 256 different odu, each associated with a spirit and certain archetypal situation. Some odu are affirmative, and others are negative.

The orbit of this binary system has an inclination between 60° and 80° from our line of sight, since dips are observed only in this inclination range. The orbital period of the system is 4.01 hours, which is the same distance in time between two consecutive dips. Like many others low- mass X-ray binaries, the luminosity of this source varies over time. Using XMM-Newton observations of Andromeda Galaxy, this source luminosity stays in the range 0.8–2.8 erg/s in the 0.2-12 keV photon energy band.

Shigeo Iwata describes the excavated weights unearthed from the Indus civilisation: The significance of a binary system of weights is that it allows an indivisible weight (eg. a gold coin or piece of jewelry) to be measured on a balance with the minimum number of weights, while the decimal system of weights and measures allows the minimum number of weights/measures to be used for bulk items by allowing repeat measures to be counted on the fingers. Rulers made from Ivory were in use by the Indus Valley Civilisation prior to 1500 BCE.

The Gliese-Jahreiss Catalogue of nearby stars designates the binary system as GJ 195. The two components are then referred to individually as GJ 195 A and B. The two stars are reported to have a 3.5 visual magnitude difference, 2.3 mag in the passband of the Gaia spacecraft, although the difference is much smaller at infrared wavelengths. This is unexpected and may indicate further unseen companions. The mass of the stars can be determined from the orbital motion, but uncertainties in the orbit have led to widely varying results.

Sigma Piscium (Sigma Psc, σ Piscium, σ Psc) is a main-sequence star in the zodiac constellation of Pisces. It has an apparent magnitude of +5.50, meaning it is barely visible to the naked eye, according to the Bortle scale. While parallax measurements by the Hipparcos spacecraft give a distance of approximately 430 light years (133 parsecs), dynamical parallax measurements put it slightly closer, at 368 light-years (113 parsecs) from Earth. Sigma Piscium is a spectroscopic binary system, meaning the components of the system have been detected from periodic Doppler shifts in their spectra.

Offalism conceptually merged Surrealism, Pop Art, Dadaism, Postmodernism and Abstract Expressionism. We created 'time capsules' indicative of our present day culture which coupled as an excellent platform for sociological information extrapolation. We had four artists instead of one, a designer, painter, photographer and writer (similar components used in magazine publishing) and neither would dictate what the other should do." "The Offal inquiry suggested that our society is overtly operating under a super-technologically enforced binary system which manifests lethargic responses using multiplicity in contradiction to our natural genealogy as human beings.

The emission above 25 keV was later found to be originating from a single source named 3XMM J004232.1+411314, and identified as a binary system where a compact object (a neutron star or a black hole) accretes matter from a star. Multiple X-ray sources have since been detected in the Andromeda Galaxy, using observations from the European Space Agency's (ESA) XMM-Newton orbiting observatory. Robin Barnard et al. hypothesized that these are candidate black holes or neutron stars, which are heating the incoming gas to millions of kelvins and emitting X-rays.

In November 2002, during the first photometric observations by Swiss astronomer Raoul Behrend at Geneva Observatory in collaboration with several other European astronomers, it was revealed that Debussy is a synchronous binary system with a minor-planet moon in orbit (F-type binary). The satellite's orbital period is 26.606 hours, identical to the primary's rotation. The system's secondary-to-primary mean-diameter ratio is 0.643. The Johnston archive derives a diameter of 9.39 kilometers for the moon, and estimates that it has a semi-major axis of approximately 31 kilometers.

Both stars in the KZ Andromedae system are main sequence stars of spectral type K2Ve, meaning that the spectrum shows strong emission lines. This is caused by their active chromosphere that cause large spots on the surface. KZ Andromedae is listed in the Washington Double Star Catalog as the secondary component in a visual binary system, with the primary being HD 218739. In 50 years of observations, there is little evidence of relative motion between the two stars; however, they have a common proper motion and a similar radial velocity.

Sigma Herculis, Latinized from σ Her, is a binary star system in the northern constellation of Hercules. It has a combined apparent visual magnitude of 4.18, making it bright enough to be visible to the naked eye. Based upon an annual parallax shift of 10.36 mas as seen from Earth, Sigma Herculis is located about 310 light years away from the Sun. The components of this binary system have a separation of 7 AU, and are orbiting their common barycenter with a period of 7.4 years and an eccentricity of 0.5.

The mixed-alkali effect: If a glass contains more than one alkali oxide, some properties show non-additive behavior. The image shows, that the viscosity of a glass is significantly decreased.The Mixed-Alkali Effect for the Viscosity of Glasses Decreasing accuracy of modern glass literature data for the density at 20 °C in the binary system SiO2-Na2O.Overview, Measurement Errors of Glass Properties Schott and many scientists and engineers afterwards applied the additivity principle to experimental data measured in their own laboratory within sufficiently narrow composition ranges (local glass models).

Shapley 1 (Sp 1 or PLN 329+2.1) is an annular planetary nebula in the constellation of Norma with a magnitude of +12.6. As viewed from Earth, it is peculiar in that it seems to be a non-bipolar, torus-shaped planetary nebula. However, it is thought that this is due to the viewpoint of looking directly down on a binary system whose orbit is perpendicular to Earth. Discovered in 1936 by Harlow Shapley, it is approximately 4900 light years from Earth, and is around 8700 years old.

Those stars have also been used as a calibration sample for Kepler candidate objects. Besides avoiding the discontinuity in the exponent at M = 0.43M⊙, the relation also recovers a = 4.0 for M ≃ 0.85M⊙. The mass/luminosity relation is important because it can be used to find the distance to binary systems which are too far for normal parallax measurements, using a technique called "dynamical parallax". In this technique, the masses of the two stars in a binary system are estimated, usually as being the mass of the Sun.

At the 59th Breslau conference in 1892, Karl Kahlbaum described paranoia based on a case study that Wernicke was familiar with. Wernicke described the case study as an example of what he called the "elementary symptom," which is the notion that there is a single, fundamental symptom and all other symptoms are derived from the elementary symptom. Karl Leonhard also followed Wernicke's studies. Although Leonhard rejected the "elementary symptom" theory because it overgeneralizes symptoms of disorders, he did incorporate Wernicke's psychopathological categories of disorders into Emil Kraepelin's binary system of classification.

A new class of white dwarfs, with spectral type DQ and hot, carbon-dominated atmospheres, has recently been discovered by Patrick Dufour, James Liebert and their coworkers. Theoretically, such white dwarfs should pulsate at temperatures where their atmospheres are partially ionized. Observations made at McDonald Observatory suggest that SDSS J142625.71+575218.3 is such a white dwarf; if so, it would be the first member of a new, DQV, class, of pulsating white dwarfs. However, it is also possible that it is a white dwarf binary system with a carbon- oxygen accretion disk.

In November 2004, a rotational lightcurve of Engelhardt was obtained from photometric observations by American astronomer Brian Warner at this Palmer Divide Observatory in Colorado. Lightcurve analysis gave a well-defined rotation period of 3.066 hours with a brightness amplitude of 0.16 magnitude (). In December 2011, a follow-up observation by Warner gave a period of 3.0661 hours with 0.18 amplitude (). Due to a couple of supposed occultation and eclipsing events, Warner also suspects that Engelhardt might by a binary system with a minor- planet moon orbiting it every 36.03 hours.

In 1836, the British government attempted to buy the design but Schilling instead accepted overtures from Nicholas I of Russia. Schilling's telegraph was tested on a experimental underground and underwater cable, laid around the building of the main Admiralty in Saint Petersburg and was approved for a telegraph between the imperial palace at Peterhof and the naval base at Kronstadt. However, the project was cancelled following Schilling's death in 1837. Schilling was also one of the first to put into practice the idea of the binary system of signal transmission.

Alpha Centauri B, also known as Toliman, is the secondary star of the binary system. It is a main-sequence star of spectral type K1 V, making it more an orange colour than Alpha Centauri A; it has around 90 percent the mass of the Sun and a 14 percent smaller diameter. Although it has a lower luminosity than A, Alpha Centauri B emits more energy in the X-ray band. Its light curve varies on a short time scale, and there has been at least one observed flare.

Circinus X-1: X-ray light rings from a binary neutron star (24 June 2015; Chandra X-ray Observatory) About 5% of all known neutron stars are members of a binary system. The formation and evolution of binary neutron stars can be a complex process.Tauris & van den Heuvel; (2006); in Compact Stellar X-ray Sources, Eds. Lewin and van der Klis, Cambridge University Press Formation and evolution of compact stellar X-ray sources Neutron stars have been observed in binaries with ordinary main-sequence stars, red giants, white dwarfs, or other neutron stars.

Hubble image of the Sirius binary system, in which Sirius B can be clearly distinguished (lower left) A binary star is a star system consisting of two stars orbiting around their common barycenter. Systems of two or more stars are called multiple star systems. These systems, especially when more distant, often appear to the unaided eye as a single point of light, and are then revealed as multiple by other means. The term double star is often used synonymously with binary star; however, double star can also mean optical double star.

However, further analysis suggests the Hipparcos measurements are not precise enough to reliably determine astrometric orbits of substellar companions, thus the orbital inclination and true mass of the candidate planet remain unknown. The radial velocity measurements of Gliese 86 show a linear trend once the motion due to this planet are taken out. This may be associated with the orbital motion of the white dwarf companion star. Star Gliese 86 B, the second star in the binary system, it is a DQ6, with a mass 0.590 of the Sun, with an 8180K temperature.

Located at an estimated distance of , this is a close binary system with a degenerate white dwarf primary in orbit with a cool red dwarf secondary over a period of 0.145143 days. Matter from the red dwarf is being drawn off onto an accretion disk orbiting the white dwarf. The mean brightness of the system varies with an amplitude of 0.5 magnitude from day to day. The observational data shows a general period of 0.037 days, which may be related to the rotation period of the white dwarf component.

MACHO-1997-BLG-41, commonly abbreviated as 97-BLG-41 or MACHO-97-BLG-41, was a gravitational microlensing event located in Sagittarius which occurred in July 1999. The source star is likely a giant or subgiant star of spectral type K located at a distance of around 8 kiloparsecs (26,000 light years). The lens star is a binary system approximately 10,000 light years away in the constellation Sagittarius. The two stars are separated from each other by about 0.9 AU and have an orbital period of around 1.5 years.

', is a non-resonant trans-Neptunian object and binary system from the Kuiper belt located in the outermost region of the Solar System, approximately in diameter. It was first observed on 18 November 1998, by American astronomer Marc Buie and Robert Millis at the Kitt Peak National Observatory in Arizona, United States. In December 2000, a minor-planet moon, designated S/2000 () 1 with a diameter of , was discovered in its orbit. After Charon in 1978, it was the first of nearly 100 satellites since discovered in the outer Solar System.

The bright binary system in Leo with orange-red and yellow or greenish-yellow components is visible through a modest telescope under good atmospheric conditions. To the naked eye, the Algieba system shines at mid-second magnitude, but a telescope easily splits the pair. The brighter component has an apparent magnitude of +2.28 and is of spectral class K1-IIIbCN-0.5. The giant K star has a surface temperature of 4,470 K, a luminosity 180 times that of the Sun, and a diameter 23 times that of the Sun.

Eta Ophiuchi is a binary system that is difficult to resolve in amateur telescopes but whose true nature was determined through use of more advanced techniques. The primary star (whose observational data make up the table in this article) is actually only slightly larger and hotter than its companion. Individually each star is a fairly unremarkable A class main sequence star, but as a binary pair they are unusual. Each star orbits around a common center in a close and highly elliptical orbit, making planetary formation unlikely in this system and some stellar data imprecise.

In 1976, Qu and his colleagues developed statistical curves on pulsar energy loss rates, and suggested that JP 1953 is a pulsar. On 5 March 1979, an intense burst of hard X-rays and γ-rays was recorded, and Qu's team analyzed its light curve and energy spectrum. They created a model for a neutron star binary system, and provided detailed explanation of the observational data using the mechanism of Bremsstrahlung and Kruskal-Schwarzschild instability. Their work was reported at the 17th International Cosmic Ray Conference held in 1981.

Gamma Canis Majoris is a blue- white B-type bright giant with a stellar classification of B8II and an apparent magnitude of +4.11. It is approximately 440 light years from Earth. It is a chemically peculiar Hg-Mg star displaying abnormal lines of mercury and magnesium. This star has 5.6 times the radius of the Sun and the outer atmosphere has an effective temperature of 13,596 K. This star is suspected of being a spectroscopic binary system, and there is a candidate companion at an angular separation of 0.332″ along a position angle of 114.8°.

It is radiating 13 times as much luminosity as the Sun from its outer atmosphere at an effective temperature of . At this heat, the star glows with the white hue of an A-type star. The space velocity components of this star in the galactic coordinate system are U = -22, V = -20 and W = -9 km/s. Data from the Hipparcos mission indicate this may be an unresolved binary system with a companion orbiting at a semimajor axis of around 1 AU, or the same distance that the Earth orbits from the Sun.

Lambda Tauri (λ Tau, λ Tauri) is a triple star system in the constellation Taurus. In the Calendarium of Al Achsasi Al Mouakket, this star was designated Sadr al Tauri, which was translated into Latin as Pectus Tauri, meaning "the bull chest". In 1848, the light from this system was found to vary periodically and it was determined to be an eclipsing binary system—the third such discovered. The components of this system have a combined apparent visual magnitude of +3.47, making it one of the brighter members of the constellation.

Zeta Tauri is a single-lined spectroscopic binary system, which means the two components are orbiting so close to each other that they can not be resolved with a telescope. Instead, the orbital motion of the primary component is indicated by Doppler effect shifts in the absorption lines in its spectrum. The two components are separated by an estimated distance of about 1.17 astronomical units, or 117% of the distance from the Earth to the Sun. They are following circular orbits with a period of nearly 133 days.

Most former polytechnics welcomed the new nomenclature of "university" as evidence of the abolition of the hierarchical binary system of universities and polytechnics. The new title also assisted recruitment of foreign students (a lucrative market sector which was not always sure what a "polytechnic" was). However, since most former polytechnics were established from locally funded technical colleges, polytechnics were, like their predecessors, controlled by and answerable to local government. The adoption of university status severed that link with the community, creating universities as semi-autonomous bodies answerable only to central government.

A helium-rich planetary object may also form from a low-mass white dwarf, which gets depleted of hydrogen via mass transfer in a close binary system with a second, massive object like a neutron star. One scenario involves an AM CVn type of symbiotic binary star composed of two helium-core white dwarfs surrounded by a circumbinary helium accretion disk formed during mass transfer from the less massive to the more massive white dwarf. After it loses most of its mass, the less massive white dwarf may approach planetary mass.

As stated previously, Darken's first equation allows the calculation of the marker velocity u in respect to a binary system where the two components have different diffusion coefficients. For this equation to be applicable, the analyzed system must have a constant concentration and can be modeled by the Boltzmann–Matano solution. For the derivation, a hypothetical case is considered where two homogeneous binary alloy rods of two different compositions are in contact. The sides are protected, so that all of the diffusion occurs parallel to the length of the rod.

Also, multiple issues arise with this theory that debates nearly-impossible steps on how the planets ended up in their current places. Thus, the scenario has been dropped. One scenario proposed a massive binary system in which the planets formed around, with the more massive companion exploding in a supernova. The neutron star would then orbit the secondary companion (forming an X-ray binary) until the now-red supergiant exceeded its Roche lobe and began spilling material onto the neutron star, with the transfer being so dramatic that it forms a Thorne–Żytkow object.

If a star is in a binary system, as is the case for Sirius B and 40 Eridani B, it is possible to estimate its mass from observations of the binary orbit. This was done for Sirius B by 1910,Preliminary General Catalogue, L. Boss, Washington, D.C.: Carnegie Institution, 1910. yielding a mass estimate of . (A more modern estimate is .)The Age and Progenitor Mass of Sirius B, James Liebert, Patrick A. Young, David Arnett, J. B. Holberg, and Kurtis A. Williams, The Astrophysical Journal 630, #1 (September 2005), pp. L69–L72.

This is an evolved K-type giant star with a stellar classification of K0 III. It has around 1−2 times the mass of the Sun and has expanded to 16.2 times the Sun's radius. The star is radiating 91 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 5,039 K. It has an A5 type magnitude 9.36 companion at an angular separation of 81.9 arc seconds along a position angle of 220°, as of 2010. The pair may form a wide binary system.

The name was later changed to Filaria sanguinis hominis perstans, and later again shortened to Filaria perstans to comply with the binary system of nomenclature. Over time, the name continued to change as changes in the generic status of the parasite took place. In 1984, Eberhard and Orihel redefined the genus Mansonella and included the M. perstans species in it, so it is currently known as M. perstans. The adult worms of M. perstans were first recovered during post mortem examination of two aboriginal Indians in British Guiana from their mesentery and subpericardial fat.

In the 1970s, dedicated X-ray astronomy satellites, such as Uhuru, Ariel 5, SAS-3, OSO-8 and HEAO-1, developed this field of science at an astounding pace. Scientists hypothesized that X-rays from stellar sources in our galaxy were primarily from a neutron star in a binary system with a normal star. In these "X-ray binaries," the X-rays originate from material traveling from the normal star to the neutron star in a process called accretion. The binary nature of the system allowed astronomers to measure the mass of the neutron star.

The binary number system was refined by Gottfried Wilhelm Leibniz (published in 1705) and he also established that by using the binary system, the principles of arithmetic and logic could be joined. Digital logic as we know it was the brain-child of George Boole in the mid 19th century. In an 1886 letter, Charles Sanders Peirce described how logical operations could be carried out by electrical switching circuits.Peirce, C. S., "Letter, Peirce to A. Marquand", dated 1886, Writings of Charles S. Peirce, v. 5, 1993, pp. 541–3.

It was and is the first research and consulting institute of its kind in the country.History of Iowa State Time Line, 1925-1949. While attempting to develop a faster method of computation, mathematics and physics professor John Vincent Atanasoff conceptualized the basic tenets of what would become the world's first electronic digital computer, the Atanasoff-Berry Computer (ABC), during a drive to Illinois in 1937. These included the use of a binary system of arithmetic, the separation of computer and memory functions, and regenerative drum memory, among others.

The binary system consists of a bright giant orbited by a dwarf companion once every four millennia or so. Compared to the Sun, Beta Draconis A is an enormous star with six times the mass and roughly 40 times the radius. At this size, it is emitting about 950 times the luminosity of the Sun from its outer envelope at an effective temperature of 5,160 K, giving it the yellow hue of a G-type star. The spectrum matches a stellar classification of G2 II, with the luminosity class of II indicating it is a bright giant.

Several KOIs contain transiting objects which are hotter than the stars they transit, indicating that the smaller objects are white dwarfs formed through mass transfer. These objects include KOI 74, KOI 81 and KOI 959. KOI 54 is believed to be a binary system containing two Class-A stars in highly eccentric orbits with a semi-major axis of 0.4 AU. During periastron, tidal distortions cause a periodic brightening of the system. In addition, these tidal forces induce resonant pulsations in one (or both) of the stars, making it only the 4th known stellar system to exhibit such behavior.

Between 240,000 and 270,000 times as luminous as the Sun, it is around 9,160 light-years distant from Earth.Table 4 in AO Cassiopeiae is a binary system composed of an O8 main sequence star and an O9.2 bright giant that respectively weigh anywhere between 20.30 and 57.75 times and 14.8 and 31.73 times the mass of the Sun. The two massive stars are so close to each other they distort each other into egg-shapes. Tycho Brahe's supernova was visible within Cassiopeia, and the star Tycho G is suspected of being the donor of the material that triggered that explosion.

KOI-74b is a hot compact object orbiting KOI-74. It was discovered in 2010 by the Kepler Mission and came to attention because of its small size (its radius is only 4.3% of the solar radius) and high temperature of . The orbit of KOI-74b around the main star takes 5.18875 days to complete. Analysis of relativistic boosting of light in the Kepler data indicates that it is likely to be a low mass white dwarf of approximately 0.22 solar masses, resulting from an earlier phase of mass transfer in a binary system when the object underwent its giant phase.

The inner pair were resolved using interferometry in 2007, and then using NACO adaptive optics with the Very Large Telescope. Photometry of the components of δ Velorum A gives apparent visual magnitudes of 2.33 and 3.44. The precise orbits allow a dynamical parallax of to be derived, representing a distance of 25.1 parsecs. Another binary system is located at an angular separation of 69 arcseconds from δ Velorum, sometimes referred to as δ Velorum C and D. The pair is composed of an 11th magnitude star and a 13th magnitude star, which are 6 arcseconds apart.

A binary system in their own right, components B and C are both rather dim red dwarf stars that have less mass, radius, and luminosity than the Sun. Component B is spectral type M1V, component C is spectral type M3V, and both emit X-rays. An artist's impression of Gliese 570 D showing the primary stars On January 15, 2000, astronomers announced that they had found one of the coolest brown dwarfs then known. Catalogued as Gliese 570 D, it was observed at a wide separation of more than 1,500 astronomical unit from the triple star system.

The pulsar is occasionally referred to as Vela X, but this phenomenon is separate from either the pulsar or the Vela X nebula. A radio survey of the Vela-Puppis region was made with the Mills Cross Telescope in 1956–57 and identified three strong radio sources: Vela X, Vela Y, and Vela Z. These sources are observationally close to the Puppis A supernova remnant, which is also a strong X-ray and radio source. Neither the pulsar nor either of the associated nebulae should be confused with Vela X-1, an observationally close but unrelated high-mass X-ray binary system.

64 Piscium is the Flamsteed designation for a close binary star system in the zodiac constellation of Pisces. It can be viewed with the naked eye, with the components having a combined apparent visual magnitude of 5.07. An annual parallax shift of 42.64 mas provides a distance estimate of 46.5 light years. The system is moving further from the Sun with a radial velocity of +3.76 km/s. This is a double-lined spectroscopic binary system consisting of two similar components designated Aa and Ab. The initial orbital elements were determined by Abt and Levy (1976), giving an orbital period of 13.8 days.

In a binary system consisting of a white dwarf and a companion star, the white dwarf strips away material from its companion. Normally the white dwarf would eventually reach a critical mass, and fusion reactions would make it explode and completely dissipate it, but in a Type Iax supernova, only half of the dwarf's mass is lost. The two inset images show before-and-after images captured by NASA's Hubble Space Telescope of Supernova 2012Z in the spiral galaxy NGC 1309. The white X at the top of the main image marks the location of the supernova in the galaxy.

The primary may itself be a close binary system with a separation of and a magnitude difference of 3.97 at an infrared wavelength of . The magnitude 5.82 primary, designated component Aa, is an A-type main-sequence star with a stellar classification of A2 V. It has 2.5 times the mass of the Sun and about 1.7 times the Sun's radius. The star is radiating 56 times the Sun's luminosity from its photosphere at an effective temperature of 9,311 K. The widely spaced secondary, designated component B, is a magnitude 7.8 A-type subgiant star with a class of A8 IV.

It has the uncommon traditional name Ghusn al Zaitun, from the Arabic الغصن الزيتون al-ghuşn al- zaitūn "the olive branch" (carried by the dove of Noah's Ark). This is a single-lined spectroscopic binary system with an orbital period of 868.78 days and an eccentricity of 0.7. It has a peculiar velocity of , making it a candidate runaway star system. The primary component is a G-type bright giant star with a stellar classification of G7 II. It radiates around 149 time the solar luminosity from its outer atmosphere at an effective temperature of 5,136 K.

Slow motion computer simulation of the black hole binary system GW150914 as seen by a nearby observer, during 0.33 s of its final inspiral, merge, and ringdown. The star field behind the black holes is being heavily distorted and appears to rotate and move, due to extreme gravitational lensing, as space-time itself is distorted and dragged around by the rotating black holes. Gravitational waves can be detected indirectly – by observing celestial phenomena caused by gravitational waves – or more directly by means of instruments such as the Earth-based LIGO or the planned space-based LISA instrument.

Discovered in 1990, UW Coronae Borealis is a low-mass X-ray binary system composed of a star less massive than the Sun and a neutron star surrounded by an accretion disk that draws material from the companion star. It varies in brightness in an unusually complex manner: the two stars orbit each other every 111 minutes, yet there is another cycle of 112.6 minutes, which corresponds to the orbit of the disk around the degenerate star. The beat period of 5.5 days indicates the time the accretion disk—which is asymmetrical—takes to precess around the star.

The origin of SX Phoenicis, and of SX Phoenicis variables in general, remains unclear. While its properties are well explained by standard stellar evolution, the observation of SX Phoenicis variables in old globular clusters indicates that these stars are blue stragglers, presumably formed by the merger of two stars or by interactions in a binary system. This explains why SX Phoenicis seems to be a young star, despite belonging to the halo population. In this scenario, SX Phoenicis was formed as a close binary star, whose components merged and originated a rejuvenated star, which started evolving as a single star.

Currently this is the only identified candidate, but it is likely that more will be found in the near future. The GAIA and LSST missions are expected to find millions more eclipsing binary system, potentially increasing the eclipsing binary database by two orders of magnitude. Recent estimates suggest that there are likely 1–10 currently observable red novae progenitors in our galaxy that will brighten as much as V1309 Scorpii on merger. Thus, if only one is currently known (KIC 9832227), then there are very likely several more out there that may be observed in the coming years.

Pluto and Charon are tidally locked to each other. Charon is massive enough that the barycenter of Pluto's system lies outside of Pluto; thus Pluto and Charon are sometimes considered to be a binary system. Tidal locking (also called gravitational locking, captured rotation and spin–orbit locking), in the best-known case, occurs when an orbiting astronomical body always has the same face toward the object it is orbiting. This is known as synchronous rotation: the tidally locked body takes just as long to rotate around its own axis as it does to revolve around its partner.

The Z3 was built with 2000 relays, implementing a 22-bit word length that operated at a clock frequency of about 5–10 Hz. Program code and data were stored on punched film. It was quite similar to modern machines in some respects, pioneering numerous advances such as floating point numbers. Replacement of the hard-to-implement decimal system (used in Charles Babbage's earlier design) by the simpler binary system meant that Zuse's machines were easier to build and potentially more reliable, given the technologies available at that time. The Z3 was probably a Turing-complete machine.

As of 1998, HY Vel and KT Vel had an angular separation of along a position angle of 311°. This is a single-lined spectroscopic binary system with an orbital period of 8.4 days and an eccentricity of 0.24. The visible component has an a sin i value of , where a is the semimajor axis and i is the (unknown) orbital inclination to the line of sight. The primary is a slowly pulsating B-type star having at least three pulsational modes, with the dominant mode showing a frequency of 0.64472 cycles per day, corresponding to the catalogued period of 1.55106 days.

This is a double-lined spectroscopic binary system, having a circular orbit with a period of 2.5 days. It was discovered to be variable independently by Friedrich Schwab and Heinrich Van Solowiew in 1913. Both components are metallic-lined, or Am stars, with a spectrum showing a deficiency of calcium and scandium, and an overabundance of heavier elements. Together they form an EA, or Algol-type, eclipsing binary with the primary occultation reducing the net magnitude to a minimum of 6.54 and the secondary eclipse lowering it to 6.43, over a cycle time of 2.52501936 days.

The net radial velocity of the system is poorly constrained, but the pair appear to be moving closer to the Earth with a heliocentric radial velocity of around −5 km/s. The variable velocity of this system was reported by Reynold K. Young from the David Dunlap Observatory in 1945. This is a double-lined spectroscopic binary system with an orbital period of 11 days and an eccentricity of 0.19. The two components are similar stars, each of 7th magnitude, with a combined stellar classification of F4 V, matching that of an F-type main sequence star.

But, in consequence, their life span on the main sequence is correspondingly shorter. For a star with a mass similar to IK Pegasi A (1.65 ), the expected lifetime on the main sequence is 2–3, which is about half the current age of the Sun. In terms of mass, the relatively young Altair is the nearest star to the Sun that is a stellar analogue of component A—it has an estimated 1.7 . The binary system as a whole has some similarities to the nearby system of Sirius, which has a class-A primary and a white dwarf companion.

On the surface of the white dwarf, the accreted gas will become compressed and heated. At some point the accumulated gas can reach the conditions necessary for hydrogen fusion to occur, producing a runaway reaction that will drive a portion of the gas from the surface. This would result in a (recurrent) nova explosion—a cataclysmic variable star—and the luminosity of the white dwarf would rapidly increase by several magnitudes for a period of several days or months. An example of such a star system is RS Ophiuchi, a binary system consisting of a red giant and a white dwarf companion.

This is a detached eclipsing binary system with the secondary eclipse being total. The pair are orbiting each other with a period of 38.81 days and an eccentricity of 0.55. The brightness of the system dips by 0.28 and 0.16 magnitude during the two eclipses per orbit. The system displays an infrared excess at a wavelength of 60 μm, indicating the presence of a circumstellar debris disk with a temperature of 120 K, orbiting at a distance of 64 AU. The pair have a combined stellar classification of A0 IV, matching a white-hued A-type subgiant.

The country's east–west distance of more than covers over 29 degrees of longitude, resulting in the sun rising and setting almost two hours earlier on India's eastern border than in the Rann of Kutch in the far west. Inhabitants of the northeastern states have to advance their clocks with the early sunrise and avoid the extra consumption of energy after daylight hours. In the late 1980s, a team of researchers proposed separating the country into two or three time zones to conserve energy. The binary system that they suggested involved a return to British-era time zones; the recommendations were not adopted.

1241–1258 with the younger components aged no more than a few million years. The complex also includes one of the hottest stars discovered within 1 kpc of the Sun, namely BD+66 1673, which is an eclipsing binary system consisting of an O5V that exhibits a surface temperature of nearly 45,000 K and a luminosity about 100,000 times that of the Sun. The star is one of the primary sources illuminating the nebula and shaping the complex's famed pillars of creation- type formations, the elephant trunks.Gahm G. F., Carlqvist P., Johansson L. E. B., Nikolić S. (2008).

IRAS 16293–2422 is a binary system consisting of at least two forming protostars A and B, separated by a distance of 700 astronomical units (au), all having masses similar to that of the Sun. It is located in the Rho Ophiuchi star-forming region, at a distance of 140 parsecs (pc). Astronomers using the ALMA array found glycolaldehyde — a simple form of sugar — in the gas surrounding the star. This discovery was the first time sugar has been found in space around a solar-type star on scales corresponding to the distance between Sun and Uranus - i.e.

The combination of greater masses and smaller separation means that the energy given off by the Hulse–Taylor binary will be far greater than the energy given off by the Earth–Sun system roughly 1022 times as much. The information about the orbit can be used to predict how much energy (and angular momentum) would be radiated in the form of gravitational waves. As the binary system loses energy, the stars gradually draw closer to each other, and the orbital period decreases. The resulting trajectory of each star is an inspiral, a spiral with decreasing radius.

In 1993, spurred in part by this indirect detection of gravitational waves, the Nobel Committee awarded the Nobel Prize in Physics to Hulse and Taylor for "the discovery of a new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation." The lifetime of this binary system, from the present to merger is estimated to be a few hundred million years. Inspirals are very important sources of gravitational waves. Any time two compact objects (white dwarfs, neutron stars, or black holes) are in close orbits, they send out intense gravitational waves.

J1808−5104 is an ultra metal-poor (UMP) star, one that has a metallicity [Fe/H] less than , 1/10,000th of the levels in the sun. It is a single-lined spectroscopic binary, with radial velocity variations in its spectral absorption lines interpreted as orbital motion of the visible star. The companion is invisible, but inferred from the orbit. J1808−5104 is the brightest UMP star, as a binary system, known, and is part of the "thin disk" of the Milky Way, the part of the galaxy in which the Sun is located, but unusual for such a metal-poor and old star.

A diagram of I Ching hexagrams sent to Gottfried Wilhelm Leibniz from Joachim Bouvet. The Arabic numerals were added by Leibniz. Leibniz, who was corresponding with Jesuits in China, wrote the first European commentary on the I Ching in 1703, arguing that it proved the universality of binary numbers and theism, since the broken lines, the "0" or "nothingness", cannot become solid lines, the "1" or "oneness", without the intervention of God. This was criticized by Hegel, who proclaimed that binary system and Chinese characters were "empty forms" that could not articulate spoken words with the clarity of the Western alphabet.

This is a double-lined spectroscopic binary system consisting of two F-type main-sequence stars with similar masses and a matching stellar classification of F5 V. Their orbital period is less than 100 days. A distant planet—HD 106906 b—is orbiting the pair at a projected separation of with a period of at least 3,000 years. An infrared excess around the binary is coming from a circumstellar debris disk that is being viewed edge-on. This has a pronounced asymmetrical shape, extending 120 AU on the east side and out to 550 AU to the west.

In 1998, the light from a supernova in NGC 3982 (later called SN 1998aq) reached earth and was discovered by British amateur astronomer Mark Armstrong. It was discovered when it had an apparent magnitude of 14.9 and it had grown considerably brighter by two days after its initial sighting (it reached a maximum magnitude of 14.0). The explosion resulted from a binary system where a white dwarf star was capturing mass from its companion star. When the white dwarf had gathered enough mass and was no longer able to support itself, the star detonated in a violent and extremely bright explosion.

A primary star, which is brighter and typically bigger than its companion stars, is designated by a capitalized A. Its companions are labelled B, C, and so on. For example, Sirius, the brightest star in the sky, is actually a double star, consisting of the naked- eye visible Sirius A and its dim white-dwarf companion Sirius B. The first exoplanet tentatively identified around the second brightest star in the triple star system Alpha Centauri is accordingly called Alpha Centauri Bb. If an exoplanet orbits both of the stars in a binary system, its name can be, for example, Kepler-34(AB) b.

An artist's impression of the HDE 226868–Cygnus X-1 binary system. ESA/Hubble illustration. HDE 226868 is a supergiant star with a spectral class of O9.7 Iab, which is on the borderline between class O and class B stars. It has an estimated surface temperature of 31,000 K and mass approximately 20–40 times the mass of the Sun. Based on a stellar evolutionary model, at the estimated distance of 2,000 parsecs this star may have a radius equal to about 15–17 times the solar radius and is approximately 300,000–400,000 times the luminosity of the Sun.

The compact object and blue supergiant star form a binary system in which they orbit around their center of mass every 5.599829 days. From the perspective of the Earth, the compact object never goes behind the other star; in other words, the system does not eclipse. However, the inclination of the orbital plane to the line of sight from the Earth remains uncertain, with predictions ranging from 27–65°. A 2007 study estimated the inclination is , which would mean that the semi-major axis is about , or 20% of the distance from the Earth to the Sun.

After the New Horizons probe completed its flyby of Arrokoth, the probe began observations of other nearby surrounding Kuiper belt objects, including . Observations of 's brightness variations at high phase angles allowed the New Horizons probe to make a rough determination of its rotation period as well as its shape. As New Horizons observed at phase angles near 90°, it displayed large variations in brightness, indicating that its shape is either extremely elongated or could be a binary system of two separated components. appeared to be possibly a separated binary in a few resolved New Horizons images, but it remains inconclusive.

The favorable economic climate of the 1980s brought a renewed demand for labour, which was filled by foreign workers. This led to an increase in the proportion of foreign permanent residents, from 14.8% in 1980 to 18.1% in 1990. Between 1991 and 1998, the Federal Council replaced the previous system of admission with a binary system that distinguished between member states of the EU/EFTA and all other countries, which largely remains in force. With this reform, the possibility of recruiting unskilled workers from non-EU/EFTA countries was abolished, with the exception of family reunification and asylum applications.

Since this is a binary system, the masses of the two neutron stars can be determined, and they are each around 1.4 times the mass of the Sun. Observations have shown that the pulsar's orbit is gradually contracting, which is generally understood to be evidence for the emission of energy in the form of gravitational waves, as described by Einstein’s theory of general relativity, causing the pulsar to reach periastron slightly early. Also, periastron advances 4° per year in longitude due to the gravitational field (thus the pulsar's periastron moves as far in a day as Mercury's moves in 1.5 million years).

In part this was due to racial discrimination by the European Americans, magnified by Virginia's having been a slave society. As the Nansemond and other tribal peoples intermarried with whites or African Americans, European Americans assumed they were no longer "Indian". But if the mother was Nansemond, she usually raised her children in their tradition. During the early 20th century, Virginia passed a law establishing a binary system of the "one drop rule", requiring each individual to be classified as white or colored (the latter covered anyone with any known African ancestry, regardless of other ancestry or cultural context).

It is a yellow-white hued supergiant of spectral type F5 Ib. The variability of T Vul was discovered in 1885 by Edwin Sawyer. Observations between 1885 and 2003 shows a small but continuous decrease in the period of variability amounting to 0.25 seconds per year. The companion star was detected in 1992; it is an A-type main-sequence star with a class of A0.8 V and 2.1 times the Sun's mass. Orbital periods of 738 and 1,745 days have been proposed for the pair, although, as of 2015, there remains doubt as to whether this is an actual binary system.

V5856 Sagittarii, or ASASSN-16ma, was a bright nova in the constellation Sagittarius discovered by All Sky Automated Survey for SuperNovae the 25th of October 2016, which peaked at magnitude of 5.4 in early November 2016. It is one of the brightest novae in recent history, and the brightest since V5668 Sagittarii in 2015. Being in one of the densest regions of the sky (the galactic core) it is nearly impossible to determine the culprit system, but due to the nature of the nova, a white dwarf and giant star binary system is the most likely origin.

Ontario Council on Articulation and Transfer (ONCAT), formerly known as the College University Consortium Council (CUCC), was established in 1996 by what is now the Ministry of Colleges and Universities. The council serves as an advisory body that helps in devising direct routes of transfers between postsecondary institutions for all students in Ontario, Canada. Ontario has a binary system of postsecondary education that consists of colleges and universities. The structure has been static and intentional for long, with only minimal mobility to offer between the two sides, which created resistance and, therefore, demanded the development of a more articulated system.

On October 23, 2009 he announced his plans to make a universal binary system similar to the one used on Mac OS X for Linux systems called FatELF. The project generated considerable controversy, with several Linux Kernel developers decrying the effort.Ryan Gordon Ends FatELF Universal Binary Effort - Slashdot Gordon announced that the project was on hold in early November 2009,Ryan Gordon Halts FatELF Project - OS News later stating that he would be willing to work on it again if he receives help from an interested party.No one will ever know it if I keep my mouth shut tight, tight, tight.

Alpha Centauri A, also known as Rigil Kentaurus, is the principal member, or primary, of the binary system. It is a solar-like main-sequence star with a similar yellowish colour, whose stellar classification is spectral type G2 V; it is slightly larger and more luminous than the Sun. Alpha Centauri A is about 10 percent more massive than the Sun, with a radius about 22 percent larger. When considered among the individual brightest stars in the sky (excluding the Sun), it is the fourth brightest at an apparent magnitude of −0.01, being slightly fainter than Arcturus at an apparent magnitude of −0.05.

Photometric periods of Algol variables matches the orbital period of the system. However, in XZ Andromedae have been observed slight period variations that can be reproduced with three different cycles of 137.5, 36.8 and 11.2 years, respectively. Each of them could be the effect of another faint body orbiting the binary system, but one of the two shorter cycles could also be an effect of magnetic interaction between stars (the Applegate mechanism). Other research states that the long cycle is instead a long-term period increase caused by mass transfer from the secondary (that fills its Roche lobe) to the primary component.

Alpha Librae is about from the Sun. The two brightest components of Alpha Librae form a double star moving together through space as common proper motion companions. The brightest member, α2 Librae, is itself a spectroscopic binary system. The second member, α1 Librae, is separated from the primary system by around . It too is a spectroscopic binary with an orbital period of 5,870 days and an angular separation of 0.383 arcseconds; equal to about 10 AU. The system may have a fifth component, the star KU Librae at a separation of 2.6°, thus forming a hierarchical quintuple star system.

This development are examined at length in Chapter Eleven, "The Fall of the Meritocracy", of The Broken Compass In her biography published in 1982, Susan Crosland said her husband had told her "If it's the last thing I do, I'm going to destroy every fucking grammar school in England. And Wales and Northern Ireland."Susan Crosland, 'Tony Crosland', 1982, p.148 Another major educational change was that presaged by his speech at Woolwich Polytechnic (now Greenwich University) establishing a 'binary system' of higher education, in which universities would be joined by polytechnic institutions which concentrated on high level vocational skills.

AO Cassiopeiae, also known as Pearce's Star, is a binary system composed of an O8 main sequence star and an O9.2 bright giant that respectively weigh anywhere between 20.30 and 57.75 times and 14.8 and 31.73 times the mass of the Sun. The AO Cas system is an eclipsing binary with a period of roughly 3.5 days, with the apparent magnitude ranging between 6.07 and 6.24. Stars of this brightness are generally just visible to the unaided eye in dark skies in semirural locations. The component stars are so close to each other they are ellipsoidal (egg-shaped).

In February 2004, a satellite orbiting the asteroid was discovered. The moon, designated S/2004 (1313) 1, measures about 11 kilometers in diameter and orbits Berna at a distance of 35 kilometer once every 25 hours and 28 minutes. Since the lightcurve is synchronized with the eclipse events, at least one body of the binary system rotates synchronously with the orbital motion. It was identified based on light-curve observations taken in February 2004 by several astronomers, including Raoul Behrend at Geneva Observatory, Stefano Sposetti, René Roy, Donald Pray, Christophe Demeautis, Daniel Matter, Alain Klotz and others.

The distance between two neutron stars in a close binary system is observed to shrink as gravitational waves are emitted. Ultimately, the neutron stars will come into contact and coalesce. The coalescence of binary neutron stars is one of the leading models for the origin of short gamma-ray bursts. Strong evidence for this model came from the observation of a kilonova associated with the short-duration gamma-ray burst GRB 130603B, and finally confirmed by detection of gravitational wave GW170817 and short GRB 170817A by LIGO, Virgo, and 70 observatories covering the electromagnetic spectrum observing the event.

Nova Eridani 2009 (apparent magnitude ~8.4) Evolution of potential novae begins with two main sequence stars in a binary system. One of the two evolves into a red giant, leaving its remnant white dwarf core in orbit with the remaining star. The second star—which may be either a main sequence star or an aging giant—begins to shed its envelope onto its white dwarf companion when it overflows its Roche lobe. As a result, the white dwarf steadily captures matter from the companion's outer atmosphere in an accretion disk, and in turn, the accreted matter falls into the atmosphere.

Some open clusters contain hot blue stars which seem to be much younger than the rest of the cluster. These blue stragglers are also observed in globular clusters, and in the very dense cores of globulars they are believed to arise when stars collide, forming a much hotter, more massive star. However, the stellar density in open clusters is much lower than that in globular clusters, and stellar collisions cannot explain the numbers of blue stragglers observed. Instead, it is thought that most of them probably originate when dynamical interactions with other stars cause a binary system to coalesce into one star.

Xi Phoenicis is known as a double star since 1834, the date of the first registered observation in the Washington Double Star Catalogue. The relative position of the two components has remained constant to this day, confirming they have a common proper motion and form a physical binary system. The secondary star has a visual apparent magnitude of 9.95 and in 2007 was located at an angular separation of 13.06 arcseconds and position angle of 252.5°, in relation to the primary. Considering the distance to the system, this corresponds to a projected separation of 875 AU between the stars.

This is a B-type main sequence star with a stellar classification of B1/B2 V. Sigma Lupi is a Helium strong star with an enhanced abundance nitrogen and an underabundance of carbon. Jerzykiewicz and Sterken (1992) showed a small amplitude variability with a period of 3.02 days. This suggests it is a close binary system forming a rotating ellipsoidal variable, although other causes such as rotational modulation can not be ruled out. There is a higher frequency photometric variability with a rate of 10.93482 per day and an amplitude of 0.0031 in visual magnitude, but the cause of this is unknown.

Obituary Harrington worked at the USNO. Another astronomer there, James W. Christy, consulted with him after discovering bulges in the images of Pluto, which turned out to be Pluto's satellite Charon. For this reason, some consider Harrington to be a co-discoverer of Charon, although Christy usually gets sole credit. By the laws of physics, it is easy to determine the mass of a binary system based on its orbital period, so Harrington was the first to calculate the mass of the Pluto-Charon system, which was lower than even the lowest previous estimates of Pluto's mass.

It is an orange subgiant of spectral type K3III around 199 light-years distant from the Solar System. A cool star with a surface temperature of 4300 K, it is 424 times as luminous as the sun and 37 times its diameter. It is 2.5 to 3 times as massive. Alpha Tucanae is a spectroscopic binary, which means that the two stars have not been individually resolved using a telescope, but the presence of the companion has been inferred from measuring changes in the spectrum of the primary. The orbital period of the binary system is 4197.7 days (11.5 years).

Located 1079 light-years distant, it is a red giant of spectral type M2III that has a diameter around 5.6 times the Sun's, and a luminosity around 2973 times that of the Sun. Another irregular variable, RX Telescopii is a red supergiant that varies between magnitudes 6.45 and 7.47, just visible to the unaided eye under good viewing conditions. BL Telescopii is an Algol-like eclipsing binary system that varies between apparent magnitudes 7.09 and 9.08 over a period of just over 778 days (2 years 48 days). The primary is a yellow supergiant that is itself intrinsically variable.

The primary star was discovered in 1927 by F. E. Ross using the refractor telescope at the Yerkes Observatory. He noticed the high proper motion of this dim 11th magnitude star in his second-epoch plates that were part of an astronomical survey started by E. E. Barnard, his predecessor at the observatory. Ross then included this new star in his eponymous catalog along with many others he discovered. The first detection of a binary system was in 1936 by Dirk Reuyl using the 26-in refractor telescope of the McCormick Observatory at the University of Virginia using astrometric analysis of photographic plates.

According to this model, a planet with around 3.5 times the mass of Jupiter orbits in a circumbinary orbit around the two stars at a distance of around 7 AU (assuming random orientation of the system). Subsequently, an independent analysis with data from five different observatories revealed that the microlensing event could be interpreted as being caused by a low-mass binary system of two red dwarf stars located in the galactic disk if one considers their orbital motion, without the need to invoke a planetary mass. A further study combining both datasets confirmed this finding. The planet is thus considered disproven.

Alhena is an evolving star that is exhausting the supply of hydrogen at its core and has entered the subgiant stage. The spectrum matches a stellar classification of A0 IV. Compared to the Sun it has 2.8 times the mass and 3.3 times the radius. It is radiating around 123 times the luminosity of the Sun from its outer envelope at an effective temperature of 9,260 K. This gives it a white hue typical of an A-class star. Alhena is a spectroscopic binary system with a period of 12.6 years (4,614.51 days) in a highly eccentric Keplerian orbit.

It likely passed within 1.14 and 3.45 light-years of the Sun some 3.9 million years ago, at around 2.5 times the mass of the Sun, it is possibly massive enough and close enough to disturb the Oort cloud. Alpha Microscopii is also an ageing yellow giant star of spectral type G7III with an apparent magnitude of 4.90. Located 400 ± 30 light-years away from Earth, it has swollen to 17.5 times the diameter of the Sun. Alpha has a 10th magnitude companion, visible in 7.5 cm telescopes, though this is a coincidental closeness rather than a true binary system.

The other side considers PSR to apply only to stars which are pulsars, not their companions, so the white dwarf should be named using the WD convention, making the pulsar PSR B1620-26, the white dwarf "WD J1623−266", and the planet "PSR B1620−26 b." Early articles used the first convention, but star catalogs have been using the second. The most recent proposal provides a nomenclature like PSR B1620−26 (AB)b, including capital letters A and B in parentheses to identify inner stellar components of binary system, followed by italic letter b referred to outer planetary companion.

The pGreen plasmids were first described in 2000 as components of a novel T-DNA binary system."pGreen: a versatile and flexible binary Ti vector for Agrobacterium-mediated plant transformation," Plant Molecular Biology 42: 819-832, 2000 The supporting web page provides supplementary information and ongoing support to researchers to request their plasmid resources. As these plasmids have been taken up by the research community, the plasmids have been developed, expanding the resources available to the community. Researchers are encouraged to contribute to this research community by submitting their vector sequence to genbank and providing a description of the plasmid on the site.

Radial velocity measurements taken at the Dominion Astrophysical Observatory in Victoria, British Columbia Canada in 1918 and 1919 led to the determination that 15 Cancri is a single-lined spectroscopic binary system. The first orbit was calculated in 1973 by Helmut Abt and Michael Snowden with a period of 585 days however later measurements showed that the orbital period was 635 days. 15 Cancri A, the visible component, is an Ap star, a chemically peculiar star with an over-abundance of iron peak elements, particularly silicon, chromium, and strontium, in its spectrum. Like all Ap stars, 15 Cancri has a strong magnetic field.

Turkey Tayac fought in World War I in France as a part of the Rainbow Division, originally made up of National Guard units to mobilize quickly. He was nearly killed by mustard gas. In 1911, in an article on the Piscataway tribe, the Catholic Encyclopedia noted that the few contemporary people who claimed to be Piscataway were "negro mongrels". This was an indication of how prominently the society used race to define identity; under racial segregation and application of the "one-drop rule", the states defined being of African descent as overriding other ancestry in the binary system.

Estimates of the combined stellar classification for this system range from F5III to F6IV, with the luminosity class of 'IV' or 'III' indicating the primary component is a subgiant or giant star, respectively. It is a member of a close binary system—a spectroscopic binary—whose components complete an orbit about their center of mass once every 1.736 days. Because the primary star is rotating rapidly, it has assumed the shape of an oblate spheroid. The ellipsoidal profile of the star, as viewed from Earth, varies over the course of an orbit causing the luminosity to vary in magnitude during the same period.

The primary, designated component A, is itself a double-lined spectroscopic binary system with an orbital period of 2.26 days and an eccentricity of 0.08. The more prominent member of this pair, component Aa, is a B-type main-sequence star with a stellar classification of B8 V. It has 3.33 times the mass of the Sun and is spinning with a projected rotational velocity of 70 km/s. Component B has a class of B9 V, an estimated 3.03 times the mass of the Sun, and is spinning rapidly with a projected rotational velocity of 275 km/s.

The system shows the high velocity kinematic properties of a population II star, but has Sun-like abundances of most elements. This is a probable astrometric binary system with poorly constrained orbital elements. The visible member, component A, is an evolved K-type giant star with a stellar classification K2 III At about 10.6 billion years of age, it has nearly the same mass as the Sun but has expanded to five times the Sun's radius. The star shines with 21 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,491 K.

Such pinwheels have been observed in the Quintuplet Cluster A composite optical/x-ray image of Eta Carinae and its surrounding nebula taken by the Chandra Space Telescope and the Hubble Space Telescope. The blue inner part of the nebula is optical emission, powered by the collision of winds from Eta Carinae and its unseen companion. Credit: Chandra Science Center and NASA. The archetype of such a colliding-wind binary system is WR 140 (HD 193793), which consists of a 20 solar mass () Wolf-Rayet star orbiting about a , spectral class O4-5 main sequence star every 7.9 years.

Stein 2051 (Gliese 169.1, G 175-034, LHS 26/27) is a nearby binary star system, containing a red dwarf (component A) and a degenerate star (white dwarf) (component B), located in constellation Camelopardalis at about 18 ly from Earth. Stein 2051 is the nearest (red dwarf + white dwarf) separate binary system (40 Eridani BC is located closer at 16.26 light-years, but it is a part of a triple star system). Stein 2051 B is the 6th nearest white dwarf after Sirius B, Procyon B, van Maanen's star, LP 145-141 and 40 Eridani B.

BL Hydri is another close binary system composed of a low mass star and a strongly magnetic white dwarf. Known as a polar or AM Herculis variable, these produce polarized optical and infrared emissions and intense soft and hard X-ray emissions to the frequency of the white dwarf's rotation period—in this case 113.6 minutes. There are two notable optical double stars in Hydrus. Pi Hydri, composed of Pi1 Hydri and Pi2 Hydri, is divisible in binoculars. Around 476 light-years distant, Pi1 is a red giant of spectral type M1III that varies between magnitudes 5.52 and 5.58.

Kepler-14 is a binary star system, which means that it is actually composed of two gravitationally bound stars that orbit a common point in space. The system is composed of a primary star, Kepler-14A, and a dimmer companion star, Kepler-14B. When the stars were observed, while searching for the planet Kepler-14b, the angular separation of the binary system made it extremely difficult to note the dimmer companion star. The stars have such a wide orbit that it takes approximately 2800 years for each star to complete a revolution around the centroid. The two stars are located approximately 980 parsecs (3,196 light years) from Earth.

The pathfinder instrument containing 61 PDCs and 30 SAS detectors was scheduled to be launched from the Esrange facility in northern Sweden during summer 2011. The flight was to be the first westward circumpolar balloon flight in the northern hemisphere in 20 years and was expected to take 17–25 days. The main targets of the pathfinder experiment are the Crab Pulsar and the high-mass X-ray binary system Cygnus X-1, which are two of the brightest objects in the energy range of PoGOLite. The mission was launched at 1:57am Thursday 7 July 2011 (23h57 GMT Wednesday 6 July 2011) from Esrange, Sweden.

KOI 126 is a triple star system comprising two low mass (0.24 and 0.21 solar masses ()) stars orbiting each other with a period of 1.8 days and a semi-major axis of 0.02 AU. Together, they orbit a star with a period of 34 days and a semi-major axis of 0.25 AU. All three stars eclipse one another which allows for precise measurements of their masses and radii. This makes the low mass stars 2 of only 4 known fully convective stars to have accurate determinations of their parameters (i.e. to better than several percent). The other 2 stars constitute the eclipsing binary system CM Draconis.

This is a visual binary system with the components orbiting each other over a period of roughly 700 years, having an eccentricity of 0.4 and a semimajor axis of 2 arc seconds. The pair have a combined spectral type that matches an A-type main sequence star with a stellar classification of A5 V. The individual components are of estimated types A1 and A6. The primary member, component A, is a magnitude 6.04 star with 1.85 times the mass of the Sun. It is radiating 38 times the Sun's luminosity from its photosphere at an effective temperature of about 7,990 K. The companion, component B, is visual magnitude 7.12.

56 Persei is at least a triple star and possibly a quadruple star system in the northern constellation of Perseus. It is visible to the naked eye as a dim point of light with a combined apparent visual magnitude of 5.77. The system is located distant from the Sun based on parallax, but is drifting closer with a radial velocity of −32 km/s. The main component is a binary system with an orbital period of 47.3 years and a semimajor axis of . The primary, designated component Aa, is an F-type main-sequence star with a stellar classification of F4V, a star that is currently fusing its core hydrogen.

When describing base in mathematical notation, the letter b is generally used as a symbol for this concept, so, for a binary system, b equals 2. Another common way of expressing the base is writing it as a decimal subscript after the number that is being represented (this notation is used in this article). 11110112 implies that the number 1111011 is a base-2 number, equal to 12310 (a decimal notation representation), 1738 (octal) and 7B16 (hexadecimal). In books and articles, when using initially the written abbreviations of number bases, the base is not subsequently printed: it is assumed that binary 1111011 is the same as 11110112.

Rho1 Arae is one of the dimmest stars with a Bayer designation, having an apparent visual magnitude of just +6.275 According to the Bortle Dark-Sky Scale, this means the star is just barely visible to the naked eye in dark rural skies. Based upon parallax measurements, it is about distant from the Sun, give or take a 50 light-year margin of error. This is a spectroscopic binary system, which means that the presence of an orbiting companion is indicated by shifts in the spectrum. However, because the primary component is spinning rapidly with a projected rotational velocity of , it is difficult to obtain reliable orbital elements.

The stochastic nature of the solar-like mode reveals itself in the instability of its frequency as time goes on and in the spread in frequency on several μHz. The contrast with the stability in frequency and the narrow frequency range of the β Cephei mode is striking. # HD 46149: Later on solar-like oscillations were even discovered in a more massive O star member of the binary system HD 46149. Constraints coming from the binary nature of the system coupled with seismic constraints led to the determination of the orbital parameters of the system as well as to the global properties of its members.

Loeb, A. and Gaudi, B.S. 2003 Astrophysical Journal 588, 117 The periodic variation in the velocity of an orbiting star will thus produce a periodic beaming variation in the light curve. Such an effect can confirm the binary nature of a system even without any detectable eclipses nor transits. One of the main advantages of the beaming effect is the possibility to determine the radial velocity directly from the light curve but very different luminosities of the binary components are required and a single radial velocity curve can only be obtained as in an SB1 binary system. The out of eclipse variations were modeled with the BEER (Beaming Ellipsoidal Reflection) algorithm.

Kapteyn b is the oldest-known potentially habitable planet, estimated to be possibly 11 billion years old. Located 1.5 degrees west southwest of Alpha, RR Pictoris is a cataclysmic variable that flared up as a nova, reaching magnitude 1.2 on 9 June 1925. Six months after its peak brightness, it had faded to be invisible to the unaided eye, and was magnitude 12.5 by 1975. RR Pictoris is a close binary system composed of a white dwarf and secondary star that orbit each other every 3.48 hours—so close that the secondary is filling up its Roche lobe with stellar material, which is then transferred onto the first star's accretion disk.

Globular clusters have a very high star density, and therefore close interactions and near-collisions of stars occur relatively often. Due to these chance encounters, some exotic classes of stars, such as blue stragglers, millisecond pulsars, and low-mass X-ray binaries, are much more common in globular clusters. A “blue straggler” is thought to form from the merger of two stars, possibly as a result of an encounter with a binary system. The resulting star has a higher temperature than comparable stars in the cluster with the same luminosity, and thus differs from the main sequence stars formed at the beginning of the cluster.

Binary stars form a significant portion of the total population of stellar systems, with up to half of all stars occurring in binary systems. Numerical simulations of globular clusters have demonstrated that binaries can hinder and even reverse the process of core collapse in globular clusters. When a star in a cluster has a gravitational encounter with a binary system, a possible result is that the binary becomes more tightly bound and kinetic energy is added to the solitary star. When the massive stars in the cluster are sped up by this process, it reduces the contraction at the core and limits core collapse.

Video simulation showing the warping of space-time and gravitational waves produced, during the final inspiral, merge, and ringdown of black hole binary system GW150914. Albert Einstein originally predicted the existence of gravitational waves in 1916, on the basis of his theory of general relativity. General relativity interprets gravity as a consequence of distortions in space-time, caused by mass. Therefore, Einstein also predicted that events in the cosmos would cause "ripples" in space-time – distortions of space-time itself – which would spread outward, although they would be so minuscule that they would be nearly impossible to detect by any technology foreseen at that time.

Mechanization and industrial-scale agriculture reduced the need for labor. Thousands of African Americans left the South in the Great Migration to Northern and Midwestern industrial cities, where they could get better jobs and escape the legal segregation and violence of the South. In the early 20th century industrialists began to harvest and process the pine and other timber in this area of the state. The Choctaw and Creek Native Americans struggled to maintain their traditional culture, in the face of years during which the state government imposed a binary system of dividing people into white and "all other" people of color (blacks and Indians).

The model developed to explain the observations was that AM Canum Venaticorum is a binary system consisting of a pair of white dwarfs in a close orbit. The primary is a more massive white dwarf composed of carbon/oxygen, whereas the secondary is a less massive white dwarf made of helium, with no hydrogen but traces of heavier elements. At the unexpectedly large distance found by the HST, the secondary would be a semi-degenerate object such as subdwarf B star. Gravitational wave radiation is causing a loss of angular momentum in the orbit, leading to the transfer of helium from the secondary to the primary as the two draw closer.

In information theory, a symbol (event, signal) of probability p contains -\log_2(1/p) bits of information. Hence, Zipf's law for natural numbers: \Pr(x) \approx 1/x is equivalent with number x containing \log_2(x) bits of information. To add information from a symbol of probability p into information already stored in a natural number x, we should go to x' such that \log_2(x') \approx \log_2(x) + \log_2(1/p), or equivalently x' \approx x/p. For instance, in standard binary system we would have x' = 2x + s, what is optimal for \Pr(s=0) = \Pr(s=1) = 1/2 probability distribution.

Furthermore, since the star lies against the rich backdrop of the Milky Way band, the telescope field of view around SS Cygni contains an abundance of useful brightness comparison stars. SS Cygni, like all other cataclysmic variables, consists of a close binary system. One of the components is a red dwarf-type star, cooler than the Sun, while the other is a white dwarf. Studies suggest that the stars in the SS Cygni system are separated (from surface to surface) by "only" 100,000 miles or less. The two stars are so close that they complete their orbital revolution in slightly over 6 1/2 hours.

The system is moving further from the Earth with a heliocentric radial velocity of +20 km/s. The primary component of this system, HD 92449, is a bright giant with a stellar classification of G5 IIa. The star radiates 1,370 times the Sun's luminosity from its photosphere at an effective temperature of 5,100 K. It shares a common proper motion with the magnitude 6.06 star HD 92463, and the pair likely form a binary system. This secondary component is a B-type main-sequence star with a class of B8 V. As of 2000, it had an angular separation of along a position angle of 105° from the primary.

This is probably a result of the extremely powerful solar wind that is generated by stars of this luminosity. The discovery of this massive star also cast some doubt on the prevailing theory that the ULX is generated by a black hole accretion disc. A calculation of the orbits of a binary system with the components detailed above suggests an orbital period of 200–300 hours, depending on the exact masses involved. However, a 2006 study found no evidence of any periodic variations at all in the luminosity of the X-ray source, although the strength does vary randomly over timescales of a few days.

This is a single-lined spectroscopic binary system, with the presence of a companion being demonstrated by shifts in the spectrum of the primary component. The pair orbit each other with a period of 490.0 days and an eccentricity of 0.14. The primary is a B-type main-sequence star with a stellar classification of B3 V. With a mass around 5.7 times that of the Sun, it is radiating 870 times the Sun's luminosity. This energy is being emitted from the outer atmosphere at an effective temperature of 17,520 K, causing it to shine with the blue-white hue of a B-type star.

This artist's impression video shows how two tiny but very dense neutron stars merge via gravitational wave radiation and then explode as a kilonova. Artist's impression of neutron stars merging, producing gravitational waves and resulting in a kilonova A kilonova (also called a macronova or r-process supernova) is a transient astronomical event that occurs in a compact binary system when two neutron stars or a neutron star and a black hole merge into each other. Kilonovae are thought to emit short gamma-ray bursts and strong electromagnetic radiation due to the radioactive decay of heavy r-process nuclei that are produced and ejected fairly isotropically during the merger process.

The central system at LoTr 5 has been known to be binary since 1983. At the center there is an evolved G-type star (IN Comae Berenices) that is often classified as a giant star or a subgiant, as well as a hot O-type subdwarf or white dwarf that is responsible for ionizing the nebula. The subdwarf is one of the hottest stars known, with an effective temperature of about K. The two stars orbit each very slowly; in fact, with an orbital period of , this is one of the longest periods for a binary system within a planetary nebula. The orbit is also moderately eccentric, at 0.249 ± 0.018.

This is equivalent to moving a distance of one light year every 14,700 years. After 5 million years, for example, this star will be separated from the Sun by more than 500 light years. A Type Ia supernova within a thousand parsecs (3300 light-years) is thought to be able to affect the Earth, but it must be closer than about 10 parsecs (around thirty light-years) to cause a major harm to the terrestrial biosphere. Following a supernova explosion, the remnant of the donor star (IK Pegasus A) would continue with the final velocity it possessed when it was a member of a close orbiting binary system.

However, the best-known flare star is UV Ceti, first observed to flare in 1948. Today similar flare stars are classified as UV Ceti type variable stars (using the abbreviation UV) in variable star catalogs such as the General Catalogue of Variable Stars. Most flare stars are dim red dwarfs, although recent research indicates that less massive brown dwarfs might also be capable of flaring. The more massive RS Canum Venaticorum variables (RS CVn) are also known to flare, but it is understood that these flares are induced by a companion star in a binary system which causes the magnetic field to become tangled.

The star was the fastest moving star ever seen in an X-ray binary system until the recent discovery of system 47 Tuc X9.Astronomers Just Found a Star Orbiting a Black Hole at 1 Percent the Speed of Light (2017) On the other hand, the black hole orbits at 'only' . The black hole in this compact pairing is at least three times more massive than the Sun, while its red dwarf companion star has a mass only 20% that of the Sun. The pair is separated by roughly a million kilometers – for comparison the distance to the Sun from Earth is about 150 million kilometers.

In other systems, the neutron star orbits so closely to its companion that its strong gravitational force can pull material from the companion's atmosphere into an orbit around itself, a mass transfer process known as Roche lobe overflow. The captured material forms a gaseous accretion disc and spirals inwards to ultimately fall onto the neutron star as in the binary system Cen X-3. For still other types of X-ray pulsars, the companion star is a Be star that rotates very rapidly and apparently sheds a disk of gas around its equator. The orbits of the neutron star with these companions are usually large and very elliptical in shape.

First, there is no need for any type of matter to be present nearby in order for the waves to be generated by a binary system of uncharged black holes, which would emit no electromagnetic radiation. Second, gravitational waves can pass through any intervening matter without being scattered significantly. Whereas light from distant stars may be blocked out by interstellar dust, for example, gravitational waves will pass through essentially unimpeded. These two features allow gravitational waves to carry information about astronomical phenomena heretofore never observed by humans. The sources of gravitational waves described above are in the low-frequency end of the gravitational-wave spectrum (10−7 to 105 Hz).

Through the 1940s, Walter Plecker of VirginiaFor the Plecker story, see and Naomi Drake of LouisianaFor Drake, see had an outsized influence. As the Registrar of Statistics, Plecker insisted on labeling mixed-race families of European-African ancestry as black. In 1924, Plecker wrote, "Two races as materially divergent as the White and Negro, in morals, mental powers, and cultural fitness, cannot live in close contact without injury to the higher." In the 1930s and 1940s, Plecker directed offices under his authority to change vital records and reclassify certain families as black (or colored) (without notifying them) after Virginia established a binary system under its Racial Integrity Act of 1924.

Cygnus X-1 belongs to a high-mass X-ray binary system, located about 6,070 light-years from the Sun, that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicularly to the disk, are carrying part of the energy of the infalling material away into interstellar space.

When two galaxies collide, the supermassive black holes at their centers are very unlikely to hit head-on, and would in fact most likely shoot past each other on hyperbolic trajectories if some mechanism did not bring them together. The most important mechanism is dynamical friction, which transfers kinetic energy from the black holes to nearby matter. As a black hole passes a star, the gravitational slingshot accelerates the star while decelerating the black hole. This slows the black holes enough that they form a bound, binary, system, and further dynamical friction steals orbital energy from the pair until they are orbiting within a few parsecs of each other.

Ophelia (minor planet designation: 171 Ophelia) is a large, dark Themistian asteroid that was discovered by French astronomer Alphonse Borrelly on 13 January 1877, and named after Ophelia in Shakespeare's Hamlet. This asteroid is a member of the Themis family of asteroids that share similar orbital elements. It probably has a primitive composition, similar to that of the carbonaceous chondrite meteorites. A 1979 study of the Algol-like light curve produced by this asteroid concluded that it was possible to model the brightness variation by assuming a binary system with a circular orbit, a period of 13.146 hours, and an inclination of 15° to the line of sight from the Earth.

'229762 Gǃkúnǁʼhòmdímà, provisional designation ', is a trans-Neptunian object and binary system from the extended scattered disc, located in the outermost region of the Solar System. It was discovered on 19 October 2007 by American astronomers Megan Schwamb, Michael Brown, and David Rabinowitz at the Palomar Observatory in California and measures approximately in diameter. This medium sized TNO appears to be representative of a class of mid-sized objects under approximately 1000 km that have not collapsed into fully solid bodies. Its 100-kilometer moon was discovered by Keith Noll, Will Grundy, and colleagues with the Hubble Space Telescope in 2008, and named Gǃòʼé ǃHú.

RZ Gruis is a nova-like binary system in the constellation Grus composed of a white dwarf and an F-type main-sequence star. It is generally of apparent magnitude of 12.3 with occasional dimming to 13.4. Its components are thought to orbit each other roughly every 8.5 to 10 hours (much longer than most nova- like variables, which have periods of around 3 to 4 hours). It belongs to the UX Ursae Majoris subgroup of cataclysmic variable star systems, where material from the donor star is drawn to the white dwarf where it forms an accretion disc that remains bright and outshines the two component stars.

It was not previously seen to be a member of the group. The cooler less luminous B class star HR 4729 (HD 108250) lies 90 arcseconds away from triple star system α Crucis and shares its motion through space, suggesting it may be gravitationally bound to it, and it is therefore generally assumed to be physically associated. It is itself a spectroscopic binary system, sometimes catalogued as component C (Acrux C) of the Acrux multiple system. Another fainter visual companion listed as component D or Acrux D. A further seven faint stars are also listed as companions out to a distance of about two arc-minutes.

SDSS J0106-1000 (full name: SDSS J010657.39-100003.3) is a binary star located about 7,800 light-years from Earth in the constellation Cetus. This system consists of two white dwarfs orbiting about each other once every 39 minutes. It was one of the shortest-period detached binary white dwarf systems known in 2011 They are separated from each other by only 32% of the radius of the Sun, so that each dwarf is tidally distorting the other. Despite their proximity to each other, this does not form an eclipsing binary system because the inclination of the orbital plane to the line of sight to the Earth is about .

Published by 台灣書房出版有限公司, 2005, . Consequently, the Chinese name for ζ Centauri itself is (, .) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 25 日 ζ Cen is a double-lined spectroscopic binary system, which indicates that the orbital motion was detected by shifts in the absorption lines of their combined spectra caused by the Doppler effect. The two stars orbit each other over a period of slightly more than eight days with an orbital eccentricity of about 0.5. The estimated angular separation of the pair is 1.4 mas.

The magnitude 5.3 primary component forms a near-contact binary system, with the components designated Aa and Ab. It has a combined class of B8V, an orbital period of , a separation of , and both components are close to co-rotating with their orbit. The larger member has 4.1 times the mass of the Sun and 2.4 times the Sun's radius, while the companion has 3.4 and 2.3 times, respectively. The pair form an eclipsing system, and it is classed as a rotating ellipsoidal variable. The third star, component B, is magnitude 6.0 and forms a visual pair, designated See 170, with the inner system.

Some doubt has surrounded the previous studies based on the speed and position of HE 0437-5439. The star would have to be at least 100 million years old to have traveled that distance from the galactic core, yet its mass and blue color indicate that it had burned only for 20 million years. These observations led to the explanation that it was part of a triple-star system consisting of two closely bound stars and one outer star. The black hole pulled the outer star away, which granted the star's momentum to the tight binary system and boosted both stars to escape velocity from the galaxy.

Both of these are themselves close binaries. X Trianguli is an eclipsing binary system that ranges between magnitudes 8.5 and 11.2 over a period of 0.97 days. RW Trianguli is a cataclysmic variable star system composed of a white dwarf primary and an orange main sequence star of spectral type K7 V. The former is drawing off matter from the latter, forming a prominent accretion disc. The system is around 1075 light-years distant. R Trianguli is a long period (Mira) variable that ranges from magnitude 6.2 to 11.7 over a period of 267 days. It is a red giant of spectral type M3.5-8e, lying around 960 light-years away.

The magazine described a two-player game where players remove any number of items from one of four rows, with the player holding the last item losing. Przekrój named this variant of nim as "Marienbad" after the 1960 French film Last Year at Marienbad (L'Année dernière à Marienbad), in which characters frequently play these mathematical duels. Podgórski became inspired by the use of the game nim in the film after reading about its principles. While sitting in a multi-hour lecture for his obligatory military study class, Podgórski decided to decipher the Marienbad algorithm and save it to a binary system which could be understood by computers.

Kepler-14 is a binary star whose two components are separated by at least 280 astronomical units, or the distance between the Earth and Sun. The estimated orbital period of the Kepler-14 binary system is approximated at 2800 years. The two stars are of nearly equal brightness, but the primary component is slightly brighter as it has a more visible apparent magnitude, or its brightness as seen from Earth. The primary star has an estimated mass of 1.51 times that of the Sun, and the secondary has an estimated mass of 1.39 times the Sun's mass. The Kepler-14 system is 980 parsecs (3,196 light years) from Earth.

HD 80606, a sun-like star in a binary system, orbits a common center of gravity with its partner, HD 80607; the two are separated by 1,200 AU on average. Research conducted in 2003 indicates that its sole planet, HD 80606 b is a future hot Jupiter, modeled to have evolved in a perpendicular orbit around 5 AU from its sun. The 4-Jupiter mass planet is projected to eventually move into a circular, more aligned orbit via the Kozai mechanism. However, it is currently on an incredibly eccentric orbit that ranges from approximately one astronomical unit at its apoapsis and six stellar radii at periapsis.

This star system has an apparent visual magnitude of +3.0, making it one of the brighter stars in the constellation and hence readily visible to the naked eye. Parallax measurements from the Hipparcos mission yield a distance estimate of around from the Sun. This is a single-lined spectroscopic binary system, which means that the pair have not been individually resolved with a telescope, but the gravitational perturbations of an unseen astrometric companion can be discerned by shifts in the spectrum of the primary caused by the Doppler effect. The pair orbit around their common center of mass once every 675 days with an eccentricity of 0.57.

Friction developed between members of the gay liberation and lesbian feminist movement due to the emphasis on sexual orientation politics through the lens of gender politics alone. Gay liberationists argued that the complexity of sexual orientation politics cannot be easily reduced to gender politics, and that women are denied rights while gay and lesbian individuals are denied existence. The theory of compulsory heterosexuality is criticized for upholding the existence of a binary gendered system and strict roles under this binary system. This criticism states that compulsory heterosexuality ignores individuals who act outside of their prescribed gender roles as well as ignoring individual agency in life.

K2-288Bb is within a binary system of two red dwarfs. The primary, K2-288A, is 52% the mass and 45% the radius of the Sun, while the secondary, K2-288B, is 33% the mass and 32% the radius. They are both much cooler and dimmer than the Sun, with temperatures of 3584 K and 3341 K, and are 0.03236 and 0.01175 times as luminous as the Sun, which has a temperature of 5772 K. Both stars are also rather metal-poor, with metallicities of -0.29 [Fe/H] for the primary, and -0.21 [Fe/H] for the secondary. In comparison, the Sun has a metallicity of 0.00 [Fe/H].

In 1930 the Southern block in Congress had the census changed to reflect their binary system and one-drop rule: every individual was classified only as either black or white, hiding the large number of mixed-race individuals in the South. The 1950 federal census instructed enumerators to make note of local populations of mixed white, black, and Indian ancestry in the eastern United States. In Holmes County, Florida, and nowhere else, 60 Dominickers were so counted, although they were designated as white on the census. In 1956, a United States Public Health Service worker, who had tabulated the 1950 census findings, made a brief visit to the area.

Although Eggleton and Tokovinin (2008) list this as a single star, according to Kunzli and North (1998) it may be a binary system with a long orbital period. The visible component has a stellar classification of F2III, matching an evolved star that has, at the age of age of 1.4 billion years, become a giant. However, it has just 2.74 times the Sun's radius and shows a high rate of spin with a projected rotational velocity of +140 km/s. The star has 1.76 times the mass of the Sun and is radiating 13 times the Sun's luminosity from its photosphere at an effective temperature of 6,848 K.

The secondary component, 99 Herculis B, is fainter by 3.35 magnitudes compared to the primary. It is a K-type main sequence star with a classification of K4 V. With 46% of the mass of the Sun, it has 74% of the Sun's radius but shines with just 14% of the Sun's luminosity. Images from the Herschel Space Observatory show that a disk of dusty debris is orbiting the barycenter at an average radius of 120 AU. Oddly, the disk appears to be misaligned with the orbital plane of the binary system. This may be the result of an interaction within another star system some time in the past.

Several attempts have been made to detect planets around the eclipsing binary system CM Draconis, itself part of the triple system GJ 630.1. The eclipsing binary has been surveyed for transiting planets, but no conclusive detections were made and eventually the existence of all the candidate planets was ruled out. More recently, efforts have been made to detect variations in the timing of the eclipses of the stars caused by the reflex motion associated with an orbiting planet, but at present no discovery has been confirmed. The orbit of the binary stars is eccentric, which is unexpected for such a close binary as tidal forces ought to have circularised the orbit.

Scholars who study the gender binary from an intersectional feminism and critical race theory perspective agree that during the process of European colonization of the U.S., a binary system of gender was created and enforced as a means of protecting patriarchal norms and upholding European nationalism. This idea of a gender as a binary is thought to be an oppressive means of reflecting differential power dynamics. Studies of Two Spirit traditions have shown that various Native American nations understand gender and sexuality in a way that directly opposes Western norms. Gender binarism also poses limitations on the adequacy of medical care provided to gender nonconforming patients.

Depending on the initial properties of the binary system, the polluted star can be found at different evolutionary stages. During its evolution, the barium star will at times be larger and cooler than the limits of the spectral types G or K. When this happens, ordinarily such a star is spectral type M, but its s-process excesses may cause it to show its altered composition as another spectral peculiarity. While the star's surface temperature is in the M-type regime, the star may show molecular features of the s-process element zirconium, zirconium oxide (ZrO) bands. When this happens, the star will appear as an "extrinsic" S star.

In addition to false positives, a transit signal can be due to a planet that is substantially larger than what is estimated by Kepler. This occurs when there are sources of light other than simply the star being transited, such as in a binary system. In cases such as these, there is more surface area producing light than is assumed, so a given transit signal is larger than assumed. Since roughly 34% of stellar systems are binaries, up to 34% of KOI signals could be from planets within binary systems and, consequently, be larger than estimated (assuming planets are as likely to form in binary systems as they are in single star systems).

Dr. Elise Furlan, leader of the Spitzer team that imaged this disk, concludes that the dust generated from the collision of rocky objects in the outer belt should eventually migrate toward the inner disk. But because the system is a double binary system, the dust particles do not evenly fill out the inner disk as expected. The disk was imaged with ALMA and the high resolution image showed that the disk is likely misaligned with the orbit of the inner binary. The long period of the orbiting inner binary could be responsible for this misalignment and any circumbinary planet forming in this disk would be misaligned with the orbit of the inner binary.

The Inuit languages, use a base-20 counting system. Students from Kaktovik, Alaska invented a new numbering notation in 1994 Danish numerals display a similar base-20 structure. The Māori language of New Zealand also has evidence of an underlying base-20 system as seen in the terms Te Hokowhitu a Tu referring to a war party (literally "the seven 20s of Tu") and Tama-hokotahi, referring to a great warrior ("the one man equal to 20"). The binary system was used in the Egyptian Old Kingdom, 3000 BC to 2050 BC. It was cursive by rounding off rational numbers smaller than 1 to , with a 1/64 term thrown away (the system was called the Eye of Horus).

Epsilon Chamaeleontis, Latinized from ε Chamaeleontis, is a naked-eye star located in the constellation Chamaeleon and is known as the star HIP 58484, HR 4583, or HD 104174, which during February 1836 Sir John Herschel found as the close double star, HJ 4486AB. Distance is 111±4 pc (362±14 light years) from the Sun, whose absolute magnitude of −0.361 and has the combined visual magnitude of +4.88. Observations throughout the 20th Century have been slowly reducing, whose latest separation is 0.364 arcsec in position angle 211°, as determined on date 1997.0905 using CCD speckle interferometry by E.P. Horch (1997). It is a likely binary system, though no formal orbit has yet been determined.

The FK Com stars are giants of spectral type K with an unusually rapid rotation and signs of extreme activity. Their X-ray coronae are among the most luminous (LX ≥ 1032 erg·s−1 or 1025 W) and the hottest known with dominant temperatures up to 40 MK. However, the current popular hypothesis involves a merger of a close binary system in which the orbital angular momentum of the companion is transferred to the primary. Pollux is the brightest star in the constellation Gemini, despite its Beta designation, and the 17th brightest in the sky. Pollux is a giant orange K star that makes an interesting color contrast with its white "twin", Castor.

A microquasar is a smaller cousin of a quasar that is a radio emitting X-ray binary, with an often resolvable pair of radio jets. LSI+61°303 is a periodic, radio-emitting binary system that is also the gamma- ray source, CG135+01. Observations are revealing a growing number of recurrent X-ray transients, characterized by short outbursts with very fast rise times (tens of minutes) and typical durations of a few hours that are associated with OB supergiants and hence define a new class of massive X-ray binaries: Supergiant Fast X-ray Transients (SFXTs). Observations made by Chandra indicate the presence of loops and rings in the hot X-ray emitting gas that surrounds Messier 87.

Generally, higher solubility is seen when solvent and solute atoms are similar in atomic size (15% according to the Hume-Rothery rules) and adopt the same crystal structure in their pure form. Examples of completely miscible binary systems are Cu-Ni and the Ag-Au face-centered cubic (FCC) binary systems, and the Mo-W body-centered cubic (BCC) binary system. Interstitial solutes in lattice Interstitial solid solutions form when the solute atom is small enough (radii up to 57% the radii of the parent atoms) to fit at interstitial sites between the solvent atoms. The atoms crowd into the interstitial sites, causing the bonds of the solvent atoms to compress and thus deform.

Xi1 Ceti (ξ1 Ceti), is a binary system located in the constellation Cetus, suspected as a ternary. In Chinese, (), meaning Circular Celestial Granary, refers to an asterism consisting of α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, the Chinese name for Xi1 Ceti itself is "the Fifth Star of Circular Celestial Granary", . AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日 The spectroscopic binary nature of Xi1 Ceti was discovered in 1901 by William Wallace Campbell using the Mills spectrograph at the Lick Observatory.

It is radiating 3.1 times the Sun's luminosity from its photosphere at an effective temperature of around 6,425 K. 6 Andromedae displays an infrared excess at a wavelength of 22 μm, which may indicate a circumstellar disk of warm dusty debris. The mass of the secondary component is roughly at or above that of the Sun. If it were a single, ordinary star, it should be readily visible as it would be just one magnitude fainter than the primary. The lack of conspicuous ultraviolet emission appears to rule out a white dwarf companion, so it may instead itself be a binary system consisting of two smaller stars having an orbital period between a week and a year.

Taylor immediately went to the National Radio Astronomy Observatory's telescopes in Green Bank, West Virginia, and participated in the discovery of the first pulsars discovered outside Cambridge. Since then, he has worked on all aspects of pulsar astrophysics. In 1974, Hulse and Taylor discovered the first pulsar in a binary system, named PSR B1913+16 after its position in the sky, during a survey for pulsars at the Arecibo Observatory in Puerto Rico. Although it was not understood at the time, this was also the first of what are now called recycled pulsars: neutron stars that have been spun-up to fast spin rates by the transfer of mass onto their surfaces from a companion star.

In September 2007, a rotational lightcurve of Jürgenstock was obtained from photometric observations by Federico Manzini at the Sozzago Astronomical Station in Italy. Lightcurve analysis gave a rotation period of hours with a brightness variation of 0.11 magnitude, indicative of a spherical rather than elongated shape (). In July 2014, a similar period determination of hours and an amplitude of 0.10 magnitude was made by Brian Warner at the Palmer Divide Station in California (). While Manzini and/or Raoul Behrend suspected it to be an asynchronous binary asteroid with a minor-planet moon in its orbit, Warner did not mention any anomalies in the lightcurve, and the Lightcurve Data Base does not flag the body as a potential binary system.

Vesta, the next-most- massive body in the asteroid belt after Ceres, was once in hydrostatic equilibrium and is roughly spherical, deviating mainly because of massive impacts that formed the Rheasilvia and Veneneia craters after it solidified. Its dimensions are not consistent with it currently being in hydrostatic equilibrium. Triton is more massive than Eris or Pluto, has an equilibrium shape, and is thought to be a captured dwarf planet (likely a member of a binary system), but no longer directly orbits the sun. Phoebe is a captured centaur that, like Vesta, is no longer in hydrostatic equilibrium, but is thought to have been so early in its history due to radiogenic heating.

However, modern surveys such as the Optical Gravitational Lensing Experiment (OGLE) observe millions of stars each night, and see microlensing many times each year. Since the alignment must be so precise, if the event lasts more than a few weeks, scientists can observe changes as the Earth moves around the sun, since this movement changes the alignment. Traditionally in astronomy, a change in view caused by the Earth's motion is called parallax, and this is the term used by researchers for this effect. However, if the source star is part of a binary system, then it too has orbital motion, and this can modify the alignment just as the Earth's movement can.

There is strong evidence that some short-duration gamma-ray bursts occur in systems with no star formation and no massive stars, such as elliptical galaxies and galaxy halos. The favored theory for the origin of most short gamma-ray bursts is the merger of a binary system consisting of two neutron stars. According to this model, the two stars in a binary slowly spiral towards each other because gravitational radiation releases energyAbbott 2007Kochanek 1993 until tidal forces suddenly rip the neutron stars apart and they collapse into a single black hole. The infall of matter into the new black hole produces an accretion disk and releases a burst of energy, analogous to the collapsar model.

The Houma were granted land by the 1790s on Bayou Terrebonne under the Spanish colonial administration, which had prohibited Indian slavery in 1764. They were never removed to a reservation and, as a small tribe, were overlooked by the federal government during the Indian Removal period of the 1830s. As a people without recognized communal land, in the 20th century, they were considered to have lost their tribal status. In addition, since 1808, following United States purchase of Louisiana, state policy required classification of all residents according to a binary system of white and non- white: all Indians in Louisiana were to be classified as free people of color in state records.

All are distant background objects fainter than 11th magnitude. The brightest of these is catalogued as component B, but the very high proper motion of Mu Cassiopeiae has caused it to almost double its distance from B. There are now two other stars brighter than magnitude 10 that are closer to Mu Cassiopeiae, although they are also background objects. The companions C and D are separated from each-other by four arc seconds and form a binary system about away. Mu Cassiopeiae itself is known as an astrometric binary, a star that is observed to oscillate due to the gravitational influence of an unseen companion, and that companion has now been resolved.

Left: unperturbed lightrays in a flat spacetime, right: Shapiro-delayed and deflected lightrays in the vicinity of a gravitating mass (click to start the animation) In a nearly static gravitational field of moderate strength (say, of stars and planets, but not one of a black hole or close binary system of neutron stars) the effect may be considered as a special case of gravitational time dilation. The measured elapsed time of a light signal in a gravitational field is longer than it would be without the field, and for moderate-strength nearly static fields the difference is directly proportional to the classical gravitational potential, precisely as given by standard gravitational time dilation formulas.

The term binary was first used in this context by Sir William Herschel in 1802, when he wrote: By the modern definition, the term binary star is generally restricted to pairs of stars which revolve around a common center of mass. Binary stars which can be resolved with a telescope or interferometric methods are known as visual binaries. For most of the known visual binary stars one whole revolution has not been observed yet, they are observed to have travelled along a curved path or a partial arc. Binary system of two stars The more general term double star is used for pairs of stars which are seen to be close together in the sky.

This paper was rediscovered in the 1970s and is now recognised as anticipating several astronomical ideas that had been considered to be 20th century innovations. Michell is now credited with being the first to study the case of a heavenly object massive enough to prevent light from escaping (the concept of escape velocity was well known at the time). Such an object, which he called a dark star, would not be directly visible, but could be identified by the motions of a companion star if it was part of a binary system. The classical minimum radius for escape assuming light behaved like particles of matter is numerically equal to the Schwarzschild Radius in general relativity.

Although generally considered a single star, there is some evidence that Xi Geminorum may instead be a spectroscopic binary system consisting of two component stars of equal mass. Xi Geminorum has a stellar classification of F5 IV-V, which is subgiant star that is in the process of evolving away from the main sequence of stars like the Sun. It has about 162% of the Sun's mass and is radiating more than 11 times the luminosity of the Sun. This energy is being emitted from the outer envelope of the star at an effective temperature of 6,464 K. This causes the star to take on the yellow-white hue common to F-type stars.

NIII and NIV emission lines are stronger than NV, and HeI lines are stronger than HeII, The Balmer series hydrogen lines and some other lines have P Cygni profiles. WR 148 is erratically variable on timescales ranging from seconds to years, but it shows consistent brightness and radial velocity variations with a period of 4.32 days. There is little doubt that it is a binary system, due to the regular variations and the presence of hard x-ray radiation from colliding winds, but the secondary is not clearly detectable in the spectrum. One proposal for a companion that would match the faint absorption features would be a B3 subgiant, but that is not compatible with the orbit.

They are moving away from the Earth with a heliocentric radial velocity of 22.5 km/s. The brighter member, designated component A, is classified as an Am star, which indicates that the spectrum shows abnormalities of certain elements. It is an estimated 560 million years old and is spinning with a projected rotational velocity of 75 The star has 2.01 times the mass of the Sun and 2.57 times the Sun's radius. It is radiating 18 times the Sun's luminosity from its photosphere at an effective temperature of 7,700 K. There is a faint, magnitude 9.49 companion at an angular separation of – component B; the pair most likely form a binary system.

The Z3 was built with 2000 relays, implementing a 22 bit word length that operated at a clock frequency of about 5–10 Hz. Program code was supplied on punched film while data could be stored in 64 words of memory or supplied from the keyboard. It was quite similar to modern machines in some respects, pioneering numerous advances such as floating point numbers. Rather than the harder-to- implement decimal system (used in Charles Babbage's earlier design), using a binary system meant that Zuse's machines were easier to build and potentially more reliable, given the technologies available at that time. The Z3 was not itself a universal computer but could be extended to be Turing complete.

Originally a star system with a magnitude of 11.43, it took twelve days to fade three magnitudes and then 18.6 years to fade to quiescence. In 1964 Robert P. Kraft ascertained that it was a binary system, recently determined to be true for several other novae at the time. The star system has settled to an average apparent magnitude of 11.4 since the 1940s, fading by around 1/100 of a magnitude per decade. Spectroscopic analysis conducted by Arenas and colleagues indicated the system consisted of a white dwarf of about 1.2 times as massive as the sun, with an accretion disk, and a companion star with about 20% of the Sun's mass.

Alpha Andromedae (α Andromedae, abbreviated Alpha And or α And), officially named Alpheratz , is located 97 light-years from the Sun and is the brightest star in the constellation of Andromeda. Located immediately northeast of the constellation of Pegasus, it is the upper left star of the Great Square of Pegasus. Although it appears to the naked eye as a single star, with overall apparent visual magnitude +2.06, it is actually a binary system composed of two stars in close orbit. The chemical composition of the brighter of the two stars is unusual as it is a mercury-manganese star whose atmosphere contains abnormally high levels of mercury, manganese, and other elements, including gallium and xenon.

9 Sagittarii is a binary system with the longest known period for a pair of class O stars at 9.1 years. The orbit is eccentric and the separation between the stars varies from 11 AU to 27 AU. The large separation means that the stellar winds of the two stars do not impact strongly and so the pair are not a strong source of x-rays. Lack of x-rays, low orbital velocities, and similar spectral types merging to a combined spectrum of O4V, mean that 9 Sgr was only confirmed to be a binary in 2012. Earlier clues such as nonthermal radio emission and periodic spectral line profile variations had prompted the detail search for a companion.

BZ Crucis is the bright star between the open clusters NGC 4609 and Hogg 15 HD 110432 is a Be star in the south-east of Crux, behind the center of the southern hemisphere's dark Coalsack Nebula. It has a stellar classification of B1IVe, which means it is a subgiant star of class B that displays emission lines in its spectrum. This is a variable star of the Gamma Cassiopeiae type, indicating it is a shell star with a circumstellar disk of gas about the equator, and has the variable star designation BZ Crucis. It is not known to be a member of a binary system, although it is probably a member of the open cluster NGC 4609.

Mu¹ Scorpii is an eclipsing binary of the Beta Lyrae type. Discovered to be a spectroscopic binary by Solon Irving Bailey in 1896, it was only the third such eclipsing pair to be discovered. This is a semidetached binary system where the secondary is close to filling its Roche lobe, or it may even be overflowing. The two stars revolve each other along a circular orbit with the components separated by 12.9 times the Sun's radius. Due to occultation of each component by the other, the apparent magnitude of the system decreased by 0.3 and 0.4 magnitudes over the course of the binary's orbit, which takes 34 hours 42.6 minutes to complete.

The first white dwarf discovered was in the triple star system of 40 Eridani, which contains the relatively bright main sequence star 40 Eridani A, orbited at a distance by the closer binary system of the white dwarf 40 Eridani B and the main sequence red dwarf 40 Eridani C. The pair 40 Eridani B/C was discovered by William Herschel on 31 January 1783. In 1910, Henry Norris Russell, Edward Charles Pickering and Williamina Fleming discovered that, despite being a dim star, 40 Eridani B was of spectral type A, or white. In 1939, Russell looked back on the discovery:White Dwarfs, E. Schatzman, Amsterdam: North-Holland, 1958. > I was visiting my friend and generous benefactor, Prof.

Zeta Sculptoris is near the Blanco 1 cluster as viewed from Earth, although parallax measurements indicate it to be substantially closer. The primary component, designated Zeta Sculptoris A, is a single-lined, low amplitude spectroscopic binary system with an orbital period of 4.8 years and an eccentricity of 0.32. The visible member of this pair is a B-type main-sequence star with a stellar classification of B5 V. It has a 13th magnitude companion, Zeta Sculptoris B, at an angular separation of 3 arcseconds along a position angle of 330° (as of 1927). Vizier catalog entry According to Eggleton and Tokovinin (2008), it is most likely gravitationally bound to the primary component.

K2-288Bb has a close orbit around the second, smaller star of the binary system. It orbits every 31.393 days at a distance of about 0.164 AU. For comparison, the Earth's Solar System's innermost planet, Mercury, orbits every 88 days at 0.38 AU. However, due to the small size of the host star, K2-288Bb is well within the habitable zone. In the unlikely possibility that the planet orbits the primary, it would have a semi-major axis of 0.231 AU and still reside in the habitable zone. K2-288Bb is probably tidally locked regardless of which star it orbits; one side of the planet would permanently face the host, while the other side would be always facing away.

Xi Aquarii is a single-lined spectroscopic binary system, which means that the presence of an unseen orbiting companion can be inferred from Doppler shifts in the spectral absorption lines. The two bodies orbit each other with a period of 8,016 days (22 y) and an eccentricity of 0.54. The primary component, Xi Aquarii A, is an A-type main sequence star with a stellar classification of A7 V. It has about 1.9 times the mass of the Sun and is rotating rapidly with a projected rotational velocity of 170 km/s. The orbital data is consistent with the secondary component, Xi Aquarii B, being either a red dwarf or a white dwarf star.

In some systems where the phenomenon has been observed, such as in CG Cygni, RT Lacertae, XY Ursae Majoris, or YY Eridani, the luminosity difference between subsequent maxima has been found to be variable, in others relatively stable. Furthermore, it has been observed in a variety of configurations, such as over-contact, semi-detached, and near contact systems alike. These factors make an explanation difficult and suggest that various mechanisms may be responsible for the effect to manifest. Several reasons have thus been proposed: an asymmetric distribution of starspots, impacts of one-way gas streams between the components of the binary system, or the flow of circumstellar matter, asymmetrically deflected due to Coriolis forces.

Announced in 2008, the eclipsing binary system HW Virginis, comprising a subdwarf B star and a red dwarf, was claimed to also host a planetary system. The claimed planets have masses at least 8.47 and 19.23 times that of Jupiter respectively, and were proposed to have orbital periods of 9 and 16 years. The proposed outer planet is sufficiently massive that it may be considered to be a brown dwarf under some definitions of the term, but the discoverers claimed that the orbital configuration implies it would have formed like a planet from a circumbinary disc. Both planets may have accreted additional mass when the primary star lost material during its red giant phase.

Beta Lyrae resolved using the CHARA array Beta Lyrae Aa is a semidetached binary system made up of a stellar class B6-8 primary star and a secondary that is probably also a B-type star. The fainter, less massive star in the system was once the more massive member of the pair, which caused it to evolve away from the main sequence first and become a giant star. Because the pair are in a close orbit, as this star expanded into a giant it filled its Roche lobe and transferred most of its mass over to its companion. The secondary, now more massive star is surrounded by an accretion disk from this mass transfer, with bipolar, jet-like features projecting perpendicular to the disk.

However, Houk and Smith-Moore (1988) give a main sequence classification of A1 V, while Abt and Morrell (1995) list it as a subgiant star with a class of A2 IV. The spectrum shows enhanced barium, possibly as a result of a previous mass transfer event. The companion, component B, is a white dwarf of class DA with an effective temperature of 36,885 K that has been cooling down for around four million years. It has an unusually low mass, 43% that of the Sun, suggesting that the white dwarf progenitor may have transferred matter to its companion. Alternative scenarios require either the evolution of a triple star system, or a binary system with highly eccentric orbit resulting in grazing interactions.

Slow motion computer simulation of the black hole binary system GW150914 as seen by a nearby observer, during 0.33 s of its final inspiral, merge, and ringdown. The star field behind the black holes is being heavily distorted and appears to rotate and move, due to extreme gravitational lensing, as spacetime itself is distorted and dragged around by the rotating black holes. General relativity, also known as the general theory of relativity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime.

During Brian Warner's initial photometric observation in February 2010 – carried out in collaboration with mentor Alan W. Harris at the Space Science Institute in La Canada, California, Petr Pravec at Ondřejov Observatory in the Czech Republic, and Joseph T. Pollock at Appalachian State University, North Carolina – it was revealed that Jedicke is a synchronous binary system with a minor-planet moon orbiting it every 16.7 hours. Based on the observed mutual eclipse/occultation events, the satellite diameter measures at least 32% of that of Jedicke (i.e. a secondary-to-primary mean-diameter ratio of ≥ 0.32), which translates into a diameter of 0.8–1.1 kilometers, depending on the underling size estimate of its primary. The "Johnstonsarchive" estimates that the moon has a semi-major axis of 4.4 kilometers.

The entire group travels into the past to do this, keeping the current versions of Deborah and Wheaton alive in the main timeline and duplicating them. They visit Wheaton’s duplicate and while slicing time, experience the world ending in a nuclear event. Ram and Noxon realize that the destroyers were not humans at all, but a sentient species from another planet. They decide to return to the starship and attempt to jump to the aliens’ planet in the past, preventing the evolution of the civilization which wipes out humanity and all life on Earth and Garden. They discover a binary system when they reach the aliens’ planet - one planet with an upright three-legged species, and one with a roach-like many-legged species.

Consequently, δ Pyxidis itself is known as (, .) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 17 日 This is an astrometric binary system, as determined by changes in the proper motion of the primary. The visible component has a stellar classification of A3 IV, indicating it has the spectrum of an A-type subgiant star that is consuming the last of the hydrogen at its core. At the age of around 296 million years, it is 92.5% of the way through its main sequence lifetime and is spinning with a projected rotational velocity of 68 km/s. The star has an estimated 1.8 times the mass of the Sun and about 1.6 times the Sun's radius.

In his original model Krzemiński interpreted the observed changes in the light curve as a consequence of the uneven luminous surface of a white dwarf. Soon, however, it turned out that in the case of U Geminorum it is not a white dwarf that is obscured. Correct model of the system was introduced by Józef Smak, which is for a binary system containing a white dwarf and filling Roche surface of star in main sequence, made the accretion disc and the so-called "hot spot" that is the place where accreting matter collides with the disc. It is the emergence of "hot spots" behind the disc and its eclipse by the secondary component that was responsible for the unusual appearance of the light curve of U Geminorum.

Sigma Aquilae is a double-lined spectroscopic binary system consisting of two massive B-type main sequence stars; each has a stellar classification of B3 V. They are detached components, which means the two stars are sufficiently distant from each other that neither fills its Roche lobe. Because the orbital plane lies close to the line of sight with the Earth, they form a Beta Lyrae-type eclipsing binary variable star system. The brightness of the pair decreases during each eclipse, which occurs with a frequency determined by their orbital period of 1.95026 days. During the eclipse of the primary component the net magnitude decreases by 0.20; the eclipse of the secondary component results in a magnitude decrease of 0.10.

The primary, component A, is an evolved G-type star with a stellar classification of G8.5III-IV, indicating that the spectrum displays mixed traits of a giant and subgiant star. At the age of 1.3 billion years, is currently on the red giant branch and is generating energy through hydrogen fusion along a shell surrounding an inert helium core. The star has around double the mass of the Sun and has expanded to more than eight times the Sun's radius. The star is radiating 40 times the solar luminosity from its photosphere at an effective temperature of 5,030 K. The secondary components B and C form a binary system that orbit each other with a period of about 244 years.

XTE J1650-500 is a binary system containing a stellar-mass black hole candidate and 2000–2001 transient binary X-ray source located in the constellation Ara. In 2008, it was claimed that this black hole had a mass of 3.8±0.5 solar masses,Smallest, lightest black hole identified Technology & science - Space - Space.com By Andrea Thompson, updated 4/1/2008 4:32:08 PM ET which would have been the smallest found for any black hole; smaller than GRO 1655-40, the then known smallest of 6.3 MSun. However, this claim was subsequently retracted;Determination of Black Hole Masses in Galactic Black Hole Binaries Using Scaling of Spectral and Variability Characteristics Shaposhnikov, Nickolai; Titarchuk, Lev; The Astrophysical Journal, Volume 699, Issue 1, pp.

Computer simulation of the black hole binary system GW150914 as seen by a nearby observer, during its final inspiral, merge, and ringdown. The star field behind the black holes is being heavily distorted and appears to rotate and move, due to extreme gravitational lensing, as space-time itself is distorted and dragged around by the rotating black holes.Credits: SXS (Simulating eXtreme Spacetimes) project A binary black hole (BBH) is a system consisting of two black holes in close orbit around each other. Like black holes themselves, binary black holes are often divided into stellar binary black holes, formed either as remnants of high-mass binary star systems or by dynamic processes and mutual capture, and binary supermassive black holes believed to be a result of galactic mergers.

His Ph.D. thesis was advised by Yakov Borisovich Zel'dovich and presented a first general-relativistic derivation of the conservative and radiation reaction forces in the Post-Newtonian expansion of the gravitational field of a binary system of two extended, massive bodies. In 1991, he obtained a Doctor of Science degree in Physics and Mathematics from Moscow State University and moved to Tokyo (Japan) in 1993 to teach astronomy in Hitotsubashi University. He was adjunct staff member in National Astronomical Observatory of Japan in 1993-1996 and a visiting professor in the same observatory in 1996-1997. Kopeikin moved to Germany in 1997 and worked in the Institute for Theoretical Physics of Friedrich Schiller University of Jena and in Max Planck Institute for Radio Astronomy until 1999.

A video explaining the significance of the 2011 discovery of a planet in the circumbinary habitable zone of Kepler-47. Some scientists argue that the concept of a circumstellar habitable zone is actually limited to stars in certain types of systems or of certain spectral types. Binary systems, for example, have circumstellar habitable zones that differ from those of single-star planetary systems, in addition to the orbital stability concerns inherent with a three-body configuration. If the Solar System were such a binary system, the outer limits of the resulting circumstellar habitable zone could extend as far as 2.4 AU. With regard to spectral types, Zoltán Balog proposes that O-type stars cannot form planets due to the photoevaporation caused by their strong ultraviolet emissions.

The center of mass (barycenter) of the Pluto–Charon system lies outside either body. Because neither object truly orbits the other, and Charon has 12.2% the mass of Pluto, it has been argued that Charon should be considered to be part of a binary system with Pluto. The International Astronomical Union (IAU) states that Charon is considered to be just a satellite of Pluto, but the idea that Charon might be classified a dwarf planet in its own right may be considered at a later date. In a draft proposal for the 2006 redefinition of the term, the IAU proposed that a planet be defined as a body that orbits the Sun that is large enough for gravitational forces to render the object (nearly) spherical.

In astronomy, the distance to a visual binary star may be estimated from the masses of its two components, the size of their orbit, and the period of their orbit about one another. A dynamical parallax is an (annual) parallax which is computed from such an estimated distance. To calculate a dynamical parallax, the angular semi-major axis of the orbit of the stars is observed, as is their apparent brightness. By using Newton's generalisation of Kepler's Third Law, which states that the total mass of a binary system multiplied by the square of its orbital period is proportional to the cube of its semi-major axis, together with the mass-luminosity relation, the distance to the binary star can then be determined.

After warfare in the Southeast in the 18th century, most of the remaining Saponi tribe members went north in 1740 for protection with the Iroquois. After the American Revolution, they relocated with the Iroquois in Canada, as they had been allies of the British. After the war and migration, the Saponi disappeared from the historical record in the Southeast, in part because of racial discrimination that often included them in records only as free people of color, when the states and federal government had no category in censuses for American Indian. This was especially true in the late 19th and early 20th century, after white Democrats regained control of state legislatures across the South and imposed a binary system of racial segregation.

Three stars make up the long narrow triangle that gives the constellation its name. The brightest member is the white giant star Beta Trianguli of apparent magnitude 3.00, lying 127 light-years distant from Earth. It is actually a spectroscopic binary system; the primary is a white star of spectral type A5IV with 3.5 times the mass of our sun that is beginning to expand and evolve off the main sequence. The secondary is poorly known, but calculated to be a yellow-white F-type main-sequence star around 1.4 solar masses. The two orbit around a common centre of gravity every 31 days, and are surrounded by a ring of dust that extends from 50 to 400 AU away from the stars.

Between 1900 and at least 1940, Eta Carinae appeared to have settled at a constant brightness at around magnitude 7.6, but in 1953 it was noted to have brightened again to magnitude 6.5. The brightening continued steadily, but with fairly regular variations of a few tenths of a magnitude. Light curve for Eta Carinae between 1972 and 2019 In 1996 the variations were first identified as having a 5.52-year period, later measured more accurately at 5.54 years, leading to the idea of a binary system. The binary theory was confirmed by observations of radio, optical, and near infrared radial velocity and line profile changes, referred to collectively as a spectroscopic event, at the predicted time of periastron passage in late 1997 and early 1998.

The inner pair of this triple star system, Lambda Tauri AB, orbit around each other with a period of 3.95 days and a low eccentricity of about 0.025. Their orbital plane is inclined by around 76° to the line of sight from the Earth, so it is being viewed from nearly edge on and the two stars form an Algol-like eclipsing binary system. The combined brightness of the pair varies from magnitude +3.37 to +3.91 as first one star and then the other pass in front of its companion. The primary member, λ Tau A, undergoes a decrease of 0.435 ± 0.050 in magnitude during an eclipse, while the secondary component, λ Tau B, decreases by 0.09–0.10 in magnitude.

Beta-3 Tucanae is a binary star which is separated from Beta-1 and Beta-2 Tucanae by 9 arcminutes on the sky, which puts the two systems at least 23 000 astronomical units (AU) or 0.37 light years apart. It's not clear how tightly Beta-3 Tucanae is gravitationally bound to the rest of the β Tucanae system, but all the stars have similar distances from Earth and have the same proper motion on the sky, indicating they are gravitationally influencing each other to some degree. Both components of the binary system are white A-type main sequence stars and they have apparent magnitudes of +5.8 and +6.0. They are separated by 0.1 arcseconds, or at least 4 astronomical units.

Having exhausted the supply of hydrogen at its core, the star has cooled and expanded off the main sequence, and now has over seven times the girth of the Sun. It is radiating 24 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,824 K. The secondary is a magnitude 10.24 star at an angular separation of from the primary along a position angle of 2°, as of 2015. The Washington Double Star Catalog (2001) notes this is an "optical pair, based on study of relative motion of the components," whereas Eggleton and Tokovinin (2008) list it as a binary system. Gaia Data Release 2 gives a parallax of for the companion, implying a distance around .

LSI+61°303 is a periodic, radio-emitting binary system that is also the gamma- ray source, CG135+01. LSI+61°303 is a variable radio source characterized by periodic, non-thermal radio outbursts with a period of 26.5 d, attributed to the eccentric orbital motion of a compact object, probably a neutron star, around a rapidly rotating B0 Ve star, with a Teff ~26,000 K and luminosity of ~1038 erg s−1. Photometric observations at optical and infrared wavelengths also show a 26.5 d modulation. Of the 20 or so members of the Be X-ray binary systems, as of 1996, only X Per and LSI+61°303 have X-ray outbursts of much higher luminosity and harder spectrum (kT ~ 10–20 keV) vs.

Achernar is the primary (or 'A') component of the binary system designated Alpha Eridani (α Eridani, abbreviated Alpha Eri, α Eri), which is the brightest star in the constellation of Eridanus, and the ninth-brightest in the night sky. The two components are designated Alpha Eridani A (the primary) and B (the secondary, also known informally as Achernar B). As determined by the Hipparcos astrometry satellite, it is approximately from the Sun. Of the ten apparent brightest stars in the night-time sky, Alpha Eridani is the hottest and bluest in color, due to Achernar being of spectral type B. Achernar has an unusually rapid rotational velocity, causing it to become oblate in shape. The secondary is smaller, of spectral type A, and orbits Achernar at a distance of roughly 12 astronomical units (AU).

This is a single-lined spectroscopic binary system, which means that only the absorption line features of one of the components can be distinguished. The components orbit each other with a period of 131.2 days and an eccentricity of 0.64. Depending on the source, the primary is either a B-type main sequence star with a stellar classification of B3 V, or a more evolved B-type subgiant star of class B3 IV. It has an angular diameter of 0.251 mas, which, at the estimated distance of this system, yields a physical size of about 4.3 times the radius of the Sun. The mass is 6.7 times that of the Sun and it shines with 1,965 times the solar luminosity from its outer atmosphere at an effective temperature of 17,880 K.

T Circini has a B-type spectrum, ranging in magnitude from 10.6 to 9.3 over a period of 3.298 days, although it is actually an eclipsing binary system rather than a pulsating star. AX is a Cepheid variable that varies between magnitudes 5.6 and 6.19 over 5.3 days. It is a yellow-white supergiant of spectral type F8II+, 1600 light-years away. BP Circini is another Cepheid variable with an apparent magnitude ranging from 7.37 to 7.71 over 2.4 days. Both cepheids are spectroscopic binaries, with companions that are blue-white stars of spectral type B6 and 5 and 4.7 solar masses respectively. BX Circini is a faint star that fluctuates between magnitudes 12.57 and 12.62 over a period of 2 hours 33 minutes. Over 99% of its composition appears to be helium.

The triple star θ Muscae A is composed of two parts: a spectroscopic binary system composed of the Wolf–Rayet star (spectral type: WC5 or 6) and an O-type main-sequence star (spectral type: O6 or O7) that orbit each other every 19 days and a blue supergiant (spectral type: O9.5/B0Iab) set about 46 milliarcseconds apart from them. If the system's estimated distance from Earth is accurate, the binary stars are about 0.5 AU apart and the supergiant about 100 AU apart from them. Although the Wolf–Rayet star dominates the spectrum, it is visually only about a quarter of the brightness of the supergiant companion. All three are highly luminous: combined, they are likely to be over a million times as luminous as the Sun.

Apep is a triple star system containing a Wolf–Rayet binary described as the "central engine", orbiting with a period of ~100 years, and a third hot supergiant star described as the "northern companion", orbiting the central engine at a distance of ~1,700 astronomical units and a period of >10,000 years. The binary at the centre of Apep is composed of two classical Wolf-Rayet stars of carbon- (WC8) and nitrogen-sequence (WN4-6b) subtypes, making Apep the strongest case of a classical WR+WR binary system in the Milky Way. Carbon- sequence Wolf-Rayet stars are unique among WR stars since they are often dust- making factories. A vast complex of stellar wind and cosmic dust surrounds the system, resembling WR 104, another Wolf-Rayet star system producing a pinwheel nebula.

The system is located approximately 148 light years away from the Sun based on parallax, This is a double-lined spectroscopic binary star which consists of two similar giant stars, each with spectral type F, orbiting each other with a period of just over 9 days and an eccentricity of 0.39. The pair form a Beta Lyrae-type eclipsing binary system, dropping by magnitude 0.04 during the primary eclipse. This system is a bright X-ray source with a luminosity of . The system displays an infrared excess suggesting the presence of two debris disks; the first has a temperature of 450 K and is orbiting at a distance of from its host star, while the second is a much cooler 40 K and orbits 187.8 AU from the system.

As the white dwarf consists of degenerate matter, the accreted hydrogen does not inflate, but its temperature increases. Runaway fusion occurs when the temperature of this atmospheric layer reaches ~20 million K, initiating nuclear burning, via the CNO cycle. Hydrogen fusion may occur in a stable manner on the surface of the white dwarf for a narrow range of accretion rates, giving rise to a super soft X-ray source, but for most binary system parameters, the hydrogen burning is unstable thermally and rapidly converts a large amount of the hydrogen into other, heavier chemical elements in a runaway reaction, liberating an enormous amount of energy. This blows the remaining gases away from the surface of the white dwarf surface and produces an extremely bright outburst of light.

Objects at this stage are known as Class I protostars, which are also called young T Tauri stars, evolved protostars, or young stellar objects. By this time, the forming star has already accreted much of its mass; the total mass of the disk and remaining envelope does not exceed 10–20% of the mass of the central YSO. When the lower-mass star in a binary system enters an expansion phase, its outer atmosphere may fall onto the compact star, forming an accretion disk At the next stage, the envelope completely disappears, having been gathered up by the disk, and the protostar becomes a classical T Tauri star. The latter have accretion disks and continue to accrete hot gas, which manifests itself by strong emission lines in their spectrum.

Rather, the increased temperature accelerates the rate of the fusion reaction, in a runaway process that feeds on itself. The thermonuclear flame consumes much of the white dwarf in a few seconds, causing a Type Ia supernova explosion that obliterates the star. In another possible mechanism for Type Ia supernovae, the double-degenerate model, two carbon–oxygen white dwarfs in a binary system merge, creating an object with mass greater than the Chandrasekhar limit in which carbon fusion is then ignited. Observations have failed to note signs of accretion leading up to Type Ia supernovae, and this is now thought to be because the star is first loaded up to above the Chandrasekhar limit while also being spun up to a very high rate by the same process.

The source in the LMC appeared extended and contained star ε Dor. The X-ray luminosity (Lx) over the range 1.5–12 keV was 6 × 1031 W (6 × 1038 erg/s). DEM L316A is located some 160,000 light-years away in the Large Magellanic Cloud The Large Magellanic Cloud (LMC) appears in the constellations Mensa and Dorado. LMC X-1 (the first X-ray source in the LMC) is at RA Dec , and is a high-mass X-ray binary (star system) source (HMXB). Of the first five luminous LMC X-ray binaries: LMC X-1, X-2, X-3, X-4 and A 0538–66 (detected by Ariel 5 at A 0538–66), LMC X-2 is the one that is a bright low-mass X-ray binary system (LMXB) in the LMC.

The discovery team and astronomers worldwide were puzzled by extreme separation from its host star, because it is not considered possible that a star's protoplanetary disk could be extensive enough to permit formation of gas giants at such a distance. To account for the separation, it is theorized that the companion formed independently from its star as part of a binary system. This proposal is somewhat problematic in that the mass ratio of ~140:1 is not in the range expected from this process; binary stars typically do not exceed a ratio of 10:1. This is still considered preferable, however, to the alternate theory that the companion formed closer to its primary and then was scattered to its present distance by gravitational interaction with another orbital object.

German astronomer Johann Elert Bode depicted it as the pendulum of the clock, while Lacaille made it one of the weights. It is an orange giant star of spectral type K2III that has swollen to around 11 times the diameter of the Sun, having spent much of its life as a white main-sequence star. At an estimated 1.55 times the mass of the Sun, it is radiating 38 times the Sun's luminosity from its photosphere at an effective (surface) temperature of 5,028K. At magnitude 4.93, Delta Horologii is the second-brightest star in the constellation, and forms a wide optical double with Alpha. Delta itself is a true binary system composed of a white main sequence star of spectral type A5V that is 1.41 times as massive as the Sun with a magnitude of 5.15 and its fainter companion of magnitude 7.29.

According to available astrophysical data for both WR 104 and its companion, eventually both stars will finally be destroyed as highly directional anisotropic supernovae, producing concentrated radiative emissions as narrow relativistic jets. Theoretical studies of such supernovae suggest jet formation aligns with the rotational axes of its progenitor star and its eventual stellar remnant, and will preferentially eject matter along their polar axes. If these jets happen to be aimed towards our solar system, its consequences could significantly harm life on Earth and its biosphere, whose true impact depends on the amount of radiation received, the number of energetic particles and the source's distance. Knowing that the inclination of the binary system containing WR 104 is roughly 12° relative to line of sight, and assuming both stars have their rotational axes similarly orientated, suggests some potential risk.

It was believed that gravitational perturbations caused by the orbiting parent stars would cause any circumbinary planets to collide with each other or be ejected out of orbit, either into one of the parent stars or away from the system. However, this discovery demonstrates that multiple planets can form around binary stars, even in their habitable zones; and while the planets in the Kepler-47 system are unlikely to harbor life, other planets orbiting around binary star systems may be habitable and could support life. Because most stars are binary, the discovery that multi-planet systems can form in such a system has impacted previous theories of planetary formation, and could provide more opportunities for finding potentially habitable exoplanets. The binary system is known to host three planets, all orbiting close to each other and larger than Earth, with no solid surface.

In celestial mechanics, the Kozai mechanism or Lidov–Kozai mechanism or Kozai–Lidov mechanism, also known as the Kozai, Lidov–Kozai or Kozai–Lidov effect, oscillations, cycles or resonance, is a dynamical phenomenon affecting the orbit of a binary system perturbed by a distant third body under certain conditions, causing the orbit's argument of pericenter to oscillate about a constant value, which in turn leads to a periodic exchange between its eccentricity and inclination. The process occurs on timescales much longer than the orbital periods. It can drive an initially near-circular orbit to arbitrarily high eccentricity, and flip an initially moderately inclined orbit between a prograde and a retrograde motion. The effect has been found to be an important factor shaping the orbits of irregular satellites of the planets, trans-Neptunian objects, extrasolar planets, and multiple star systems.

AGN where the relativistic plasma is collimated into jets which escape along the pole of the supermassive black hole Relativistic jets may provide evidence for the reality of frame-dragging. Gravitomagnetic forces produced by the Lense–Thirring effect (frame dragging) within the ergosphere of rotating black holes combined with the energy extraction mechanism by Penrose have been used to explain the observed properties of relativistic jets. The gravitomagnetic model developed by Reva Kay Williams predicts the observed high energy particles (~GeV) emitted by quasars and active galactic nuclei; the extraction of X-rays, γ-rays, and relativistic e−–e+ pairs; the collimated jets about the polar axis; and the asymmetrical formation of jets (relative to the orbital plane). The Lense–Thirring effect has been observed in a binary system that consists of a massive white dwarf and a pulsar.

If a planet orbits one member of a binary star system, then an uppercase letter for the star will be followed by a lowercase letter for the planet. Examples are 16 Cygni Bb and HD 178911 Bb. Planets orbiting the primary or "A" star should have 'Ab' after the name of the system, as in HD 41004 Ab. However, the "A" is sometimes omitted; for example the first planet discovered around the primary star of the Tau Boötis binary system is usually called simply Tau Boötis b. The star designation is necessary when more than one star in the system has its own planetary system such as in case of WASP-94 A and WASP-94 B. If the parent star is a single star, then it may still be regarded as having an "A" designation, though the "A" is not normally written.

X-ray bursters are one class of X-ray binary stars exhibiting periodic and rapid increases in luminosity (typically a factor of 10 or greater) that peak in the X-ray regime of the electromagnetic spectrum. These astrophysical systems are composed of an accreting compact object, and a main sequence companion 'donor' star. A compact object in an X-ray binary system consists of either a neutron star or a black hole; however, with the emission of an X-ray burst, the companion star can immediately be classified as a neutron star, since black holes do not have a surface and all of the accreting material disappears past the event horizon. The donor star's mass falls to the surface of the neutron star where the hydrogen fuses to helium which accumulates until it fuses in a burst, producing X-rays.

Environmental engineering began offering undergraduate degrees; agricultural engineering focused on water conservation and irrigation; coastal engineers were looking to stabilize Florida's coastlines; nuclear engineering was studying the feasibility of offshore power plants; and mechanical engineering became a national leader in solar energy studies. Former Dean Weil Computers were changing the nature of research within the college. The departments of Industrial & Systems Engineering, Electrical Engineering and Computer & Information Sciences were doing advanced research in computer-related fields. This shift began with an engineer: UF alumnus John Vincent Atanasoff. In 1973, Atanasoff was credited as the originator of the modern computer. He had created a prototype of the first digital calculator in 1939, and it possessed many features of modern computers--a binary system, regenerative memory, logical schemes as elements of software and electronic components for storing data.

The habitable zone of the Kepler-16 system extends from approximately 55 to 106 million kilometers away from the binary system. Kepler-16b, with an orbit of about 104 million kilometers, lies near the outer edge of this habitable zone. Although the chances of life on the gas giant itself are remote, simulations conducted by researchers at the University of Texas suggest that sometime in the system's history, perturbations from other bodies could have caused an Earth-sized planet from the center of the habitable zone to migrate out of its orbit, allowing Kepler-16b to capture it as its moon. Furthermore, the researchers also considered the possibility of a faraway habitable planet orbiting at about 140 million kilometers away, which could retain the thermal energy needed to keep water liquid through a thick mixture of greenhouse gases including carbon dioxide and methane.

Either the liberation could cause asteroids to be scattered towards the white dwarf or the exomoon could be scattered into the Roche-Radius of the white dwarf. The mechanism behind the pollution of white dwarfs in binaries was also explored as these systems are more likely to lack a major planet, but this idea cannot explain the presence of dust around single white dwarfs. While old white dwarfs show evidence of dust accretion, white dwarfs older than ~1 billion years or >7000 K with dusty infrared excess were not detected until the discovery of LSPM J0207+3331 in 2018, which has a cooling age of ~3 billion years. The white dwarf shows two dusty components that are being explained with two rings with different temperatures. There is a planet in the white dwarf–pulsar binary system PSR B1620-26.

In a positional numeral system, the radix or base is the number of unique digits, including the digit zero, used to represent numbers. For example, for the decimal/denary system (the most common system in use today) the radix (base number) is ten, because it uses the ten digits from 0 through 9. In any standard positional numeral system, a number is conventionally written as with x as the string of digits and y as its base, although for base ten the subscript is usually assumed (and omitted, together with the pair of parentheses), as it is the most common way to express value. For example, (100)10 is equivalent to 100 (the decimal system is implied in the latter) and represents the number one hundred, while (100)2 (in the binary system with base 2) represents the number four.

Stellar evolution modelling has concluded that the system likely begun as a binary system, with one star about double the Sun's mass and the other roughly equivalent to that of the sun. The larger star eventually aged and expanded as it used up its core hydrogen, and begun having its mass siphoned off by the smaller star; the system is likely to have been an Algol-type eclipsing binary at this stage. This star appears now to be an aged star composed mostly of helium with very little hydrogen and with a mass of 0.2 solar masses and around 37 times the luminosity of the Sun and surface temperature of 7000 K, while the once-smaller star is the Delta Scuti variable that is now around two solar masses. Around 0.8 solar masses has been lost from the system over time.

In 2013 he led the team that measured the mass of the neutron star in the binary system PSR J0348+0432. This measurement confirmed the existence of supermassive neutron stars and made possible a new test of Einstein's theory of general relativity. In 2016, Antoniadis together with André van Staden, a South African amateur astronomer, announced the discovery of magnetic activity on the surface of the companion star of a millisecond pulsar. In 2014, Antoniadis was awarded the Otto Hahn Medal by the Max Planck Society, the Dissertation Prize of the Deutsche Physikalische Gesellschaft and the Best Thesis Award from the Foundation for Physics and Astronomy in Bonn. His thesis was included in the “outstanding theses” series by Springer Nature In 2016 he received the John Charles Polanyi Prize for Physics by the Council of Ontario Universities.

Studies of the trajectory and speed of BD+43 3654 relative to the other stars of the nearby, massive stellar association Cygnus OB2 suggest it is a runaway star, making it one of the most massive runaway stars known in the Milky Way (along with the O-type supergiants Lambda Cephei and Zeta Puppis). Initially it was suggested a supernova explosion of a former binary system companion star caused the high velocity of BD+43 3654. Later research shows that a supernova ejection would not produce such a high space velocity. Given that BD+43 3654 appears to be younger than most stars in Cygnus OB2, an alternative scenario has been proposed in which BD+43 3654 is a massive blue straggler born in an encounter between two former double stars in the core of Cygnus OB2.

The primary member of the group, designated component A, is a single-lined spectroscopic binary system with an orbital period of 3.88 days and a negligible eccentricity. The visible component of this pair is a magnitude 4.49 A-type main-sequence star with a stellar classification of A1 V. It has 3.2 times the mass of the Sun and is spinning with a projected rotational velocity of 40 km/s. The star is radiating 222 times the Sun's luminosity from its photosphere at an effective temperature of 9,226 K. The magnitude 7.90 component B has an orbital solution with the Aa/Ab pair, which yields a period of 284 years and an eccentricity of 0.74. However, Drummond (2014) found the data to be discordant and instead determined that they are an optical pair with no physical association.

For the reader who desires a deeper background, a comprehensive review of the definition of the speed of gravity and its measurement with high-precision astrometric and other techniques appears in the textbook Relativistic Celestial Mechanics in the Solar System. ;PSR 1913+16 orbital decay: The speed of gravity (more correctly, the speed of gravitational waves) can be calculated from observations of the orbital decay rate of binary pulsars PSR 1913+16 (the Hulse–Taylor binary system noted above) and PSR B1534+12. The orbits of these binary pulsars are decaying due to loss of energy in the form of gravitational radiation. The rate of this energy loss ("gravitational damping") can be measured, and since it depends on the speed of gravity, comparing the measured values to theory shows that the speed of gravity is equal to the speed of light to within 1%.

Consequently, the Chinese name for χ Andromedae itself is (, .) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 10 日 This is most likely a spectroscopic binary system with an estimated orbital period of 21.5 years and an eccentricity of 0.37. The primary component has a stellar classification of G8 III, which indicates it is a giant star that has exhausted the supply of hydrogen at its core and evolved away from the main sequence. The outer envelope has expanded to about nine times the radius of the Sun and it is radiating 47 times the luminosity of the Sun at an effective temperature of 5,070 K. This heat gives the star the yellow-hued glow of a G-type star. It appears to be rotating very slowly with no measurable projected rotational velocity.

SINFONI also measured the apparent magnitude of the system in the K band as for the central engine and for C, in the L band as for the central engine and for the northern companion, and in the M band as for the central engine and for the northern companion. SINFONI observations further detailed that the northern companion is possibly a conventional B1Ia+ high luminosity star. A and B show a typical spectrum from a WC7 star, but with additional WN4 or WN5 star features theorised to be from one of the stars of the central engine; if confirmed, this would make Apep a rare binary system of WR stars. An alternative hypothesis also based on SINFONI data proposes that the spectra could all be from an unusual transitional WN/WC star, and that the northern companion would then be a conventional OB star.

The Technetium isotope produced by neutron capture in the s-process is 99Tc and it has a half life of around 200,000 years in a stellar atmosphere. Any of the isotope present when a star formed would have completely decayed by the time it became a giant, and any newly formed 99Tc dredged up in an AGB star would survive until the end of the AGB phase, making it difficult for a red giant to have other s-process elements in its atmosphere without technetium. S-type stars without technetium form by the transfer of technetium-rich matter, as well as other dredged-up elements, from an intrinsic S star in a binary system onto a smaller less-evolved companion. After a few hundred thousand years, the 99Tc will have decayed and a technetium-free star enriched with carbon and other s-process elements will remain.

While it is not impossible that some binaries might be created through gravitational capture between two single stars, given the very low likelihood of such an event (three objects being actually required, as conservation of energy rules out a single gravitating body capturing another) and the high number of binaries currently in existence, this cannot be the primary formation process. The observation of binaries consisting of stars not yet on the main sequence supports the theory that binaries develop during star formation. Fragmentation of the molecular cloud during the formation of protostars is an acceptable explanation for the formation of a binary or multiple star system. The outcome of the three-body problem, in which the three stars are of comparable mass, is that eventually one of the three stars will be ejected from the system and, assuming no significant further perturbations, the remaining two will form a stable binary system.

V603 Aquilae (or Nova Aquilae 1918) was a bright nova first observed (from Earth) in the constellation Aquila in 1918. It is a binary system, comprising a white dwarf and donor low-mass star in close orbit to the point of being only semidetached. The white dwarf sucks matter off its companion, which has filled its Roche lobe, onto its accretion disk and surface until the excess material is blown off in a thermonuclear event. This material then forms an expanding shell, which eventually thins out and disappears. First seen by Zygmunt Laskowski, a medical professor and amateur astronomer,The Contribution of Amateurs to Astronomy, Proceedings of Colloquium 98 of the International Astronomical Union, June 20–24, 1987, page 41 and then confirmed on the night of 8 June 1918 by the UK amateur astronomer Grace Cook, The nova is estimated at between 784 to 839 light years distance from Earth .

The Mangarevan people developed a binary number system centuries ahead of Europeans. In 2013, the islanders were discovered to have developed a novel binary system that allowed them to reduce the number of digits involved in binary counting: for example, representing 150 requires eight digits in binary (10010111) but only four in the Mangarevan system (VTPK, where V (varu) means 80, T (tataua) is 40, P (paua) is 20, and K (takau) is 10). As binary counting is unknown in other Polynesian societies, it most likely formed after Mangareva was settled between 1060 and 1360 AD. Since Gottfried Leibniz would not invent the modern binary number system until 1689, the Mangarevan binary steps prefigured the European invention of binary by as many as 300 to 600 years. In 2020, Mangarevan binary counting was shown to be an extension of a traditional Polynesian method of counting.

Theta Muscae is a triple star system thought to be around 7,500 light-years distant. It consists of a spectroscopic binary system composed of the Wolf–Rayet star (spectral type: WC5 or 6) and an O-type main-sequence star (spectral type: O6 or O7) that orbit each other every 19 days and a blue supergiant (spectral type: O9.5/B0Iab) set about 46 milliarcseconds apart from them. If the system's estimated distance from Earth is accurate, the binary stars are about 0.5 astronomical units (AU) apart and the supergiant about 100 AU apart from them. All three are highly luminous; combined, they are likely to be over a million times as luminous as the Sun. TU Muscae is a binary star system located around 15,500 light-years away made up of two hot, luminous, blue main-sequence stars of spectral types O7.5V and O9.5V, with masses 23 and 15 times that of the Sun.

Its mass was originally estimated at 14 MJ, very close to the nominal boundary between planets and brown dwarf, but a recent revision of the age of the Upper Scorpius association to 11 million years increased this value to 16 MJ, indicating that the object is likely a low mass brown dwarf. The physical association between the two brown dwarfs has not been confirmed by observation of common proper motion, but is considered very likely given the proximity between them. The minimum separation between the two brown dwarfs, 670 AU, is much larger than the mean of other similar mass systems, and indicates that the pair (if they really form a binary system) is very weakly bound, with an escape velocity for the secondary component of only 0.4 km/s. Considering the average stellar density in an association like Upper Scorpius, it is estimated that perturbations by passing stars will cause the rupture of the system in a few million years.

UScoCTIO 108 is a binary system, approximately 470 light-years away in the Upper Scorpius (USco) OB association. The primary, UScoCTIO 108A, with mass around 0.06 solar masses, is a brown dwarf or low-mass red dwarf. The secondary, UScoCTIO 108B, with a mass around the deuterium burning limit of 13 Jupiter masses, would be classified as either a brown dwarf or an extrasolar planet. The primary component of the system was discovered in 2000 as a possible member of the Upper Scorpius association, based on its position in a HR diagram, in a search for new member of the association by the Cerro Tololo Inter-American Observatory (CTIO), where it received the designation UScoCTIO 108. Later, spectroscopic and photometric observations confirmed that the object is a real member of the association, showing signs of low gravity and youth, and estimated a mass of 60 times the mass of Jupiter (MJ), an effective temperature of 2,800 K and a spectral type of M7.

The first white dwarf discovered was in the triple star system of 40 Eridani, which contains the relatively bright main sequence star 40 Eridani A, orbited at a distance by the closer binary system of the white dwarf 40 Eridani B and the main sequence red dwarf 40 Eridani C. The pair 40 Eridani B/C was discovered by William Herschel on January 31, 1783;Catalogue of Double Stars, William Herschel, Philosophical Transactions of the Royal Society of London 75 (1785), pp. 40–126, p. 73 it was again observed by Friedrich Georg Wilhelm Struve in 1825 and by Otto Wilhelm von Struve in 1851.The orbit and the masses of 40 Eridani BC, W. H. van den Bos, Bulletin of the Astronomical Institutes of the Netherlands 3, #98 (July 8, 1926), pp. 128–132.Astrometric study of four visual binaries, W. D. Heintz, Astronomical Journal 79, #7 (July 1974), pp. 819–825.

In Boden et al. (1999), the full set of orbital elements were derived using measurements with the Palomar Testbed Interferometer. Nadal et al. (1979) suggested that some variation in the measurements may be caused by a third component in the system, but this was not supported by the results from Boden et al. (1999). In 2005, Maciej Konacki pioneered a new technique for accurately determining the radial velocity of a double-lined binary system, which allowed the elements to be further refined. This yielded an orbital period of 13.82449 days, an eccentricity of 0.2366, and an angular semimajor axis of 6.55 mas. Both stars in this system have a spectrum matching a stellar classification of F8 V, indicating they are ordinary F-type main-sequence stars that are generating energy via hydrogen fusion at their cores. The orbital measurements of this system allows the masses of the two stars to be determined accurately: the primary component has 1.22 times the mass of the Sun while the secondary has 1.17 times the Sun's mass.

Naomi Ruth née Mason Drake (12 February 1907 – 22 February 1987) was an American who became notable in mid-20th century Louisiana as the Registrar of the Bureau of Vital Statistics for the City of New Orleans (1949–1965), where she imposed strict racial classifications on people under a binary system that recognized only "white" and "black" (or all other.) She unilaterally changed records to classify mixed-race individuals as black if she found they had any black (or African) ancestry, an application of hypodescent rules, and did not notify people of her actions.Virginia R. Domínguez, White by Definition: Social Classification in Creole Louisiana, New Brunswick, NJ: Rutgers University Press, 1986 In other cases, if people would not accept her racial classification, she refused to release the requested birth or death certificate. Her insistence on changing records to classify persons of any suspected African descent was similar to the racial zealotry demonstrated by Dr. Walter Plecker, state registrar of Virginia's Vital Statistics, and a major lobbyist for its Racial Integrity Act of 1924.

NGC 6544 is a globular cluster of medium density, estimated value of 5 on a scale between 1 and 12; its distance is estimated at 2900 parsecs (9450 light years) from the Sun, which in its position corresponds to a distance of 6100 parsecs from the center of the Milky Way and only 100 parsecs from the galactic plane, to the point of being one of the closest globular clusters to known galactic plane. Its small angular size, equal to just under 4' for the main body storage and corresponding to just 3.2 parsecs, making it also one of the smaller globular clusters known. In 1999 she was discovered within the cluster a pulsar in a binary system of type millisecond, cataloged as PSR J1807-2459; There are few notes variable stars part of this cluster; a 1993 study focused on the region around NGC 6544 has identified some variable stars, of which only one is found to belong in storage: it is a RR Lyrae variable with a period of 0.57 days.

A white giant of spectral class A7III, it is an aging star that has used up the hydrogen fuel at its core and has expanded and cooled after moving off the main sequence. It lies 135 light years away from the Solar System. Lying a few degrees west of Beta is Delta Pavonis, a nearby Sun-like but more evolved star; this is a yellow subgiant of spectral type G8IV and apparent magnitude 3.56 that is only 19.9 light years distant from Earth. East of Beta and at the constellation's eastern border with Indus is Gamma Pavonis, a fainter, solar-type star 30 light years from Earth with a magnitude of 4.22 and stellar class F9V. Other nearby stars in Pavo are much fainter: SCR 1845-6357 (the nearest star in Pavo) is a binary system with an apparent magnitude of 17.4 consisting of a red dwarf and brown dwarf companion lying around 12.6 light years distant, while Gliese 693 is a red dwarf of magnitude 10.78 lying 19 light years away.

Additionally, the university has responsibility for CNAA records. The CNAA, through its many subject panels, oversaw the degree-awarding powers of polytechnics. Above all, the CNAA saw itself as preserving a comparability at the national level with degree level awards in universities, a feature which can be seen as having both positive and negative aspects: positive in that it preserved a formal "parity of esteem" between the awards of the two parts of the binary system (such as retaining the common currency of the undergraduate degree for entry to postgraduate study), but other scholarsPratt, 1997. viewed it as negative because it encouraged an "academicism" in the new sector and slowed an acceptance of the transformations required finally to break the boundaries of the old, "elite" system. In the event, the polytechnics were associated with many innovations, including women’s studies, the academic study of communications and media, sandwich degrees, advanced engineering degrees in all functional specialities, and the rise of management and business studies; not least, they were much more responsive than older institutions in providing for the admission of non-standard students from technical colleges, advanced apprenticeships and other sources.

Since the Bronze Age, ratti (0.11 or 0.12 gm) or the weight of the Gunja seeds have been used as a base unit for the measurement of mass in the Indus Valley civilization, the smallest weight of Indus was equal to 8 rattis (0.856 gm) and the binary system was used for the multiple of weights for instance 1:2:4:8:16:32, the 16th ratio being the standard regular weight (16 x smallest weight) etc. . This weight system seems to have been replicated in the earliest Indian coins. The Masha coins were quarter Karshapanas, karshapanas themselves being the quarter value of Karsha (13.7 gm, 128 ratti) or 32 ratti which is the same as the regular weight used in the Indus Valley civilization, This standard (of 32 rattis) has been declared as Purana or Dharana by Kautilya. The Karsha weight differed based on the differing values of mashas, for instance arthashastra mentions a masha equal to 5 ratti as opposed to 8 ratti mashas which is described as the prevalent standard during Kautilya's time. The Gandharan quarter svarna coins conform to a different 5 ratti mashas system mentioned in the Arthashastra as do the copper punch marked coins (80 ratti, 146 grain, 9.46 gm).