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"celestial sphere" Definitions
  1. an imaginary sphere of infinite radius against which the celestial bodies appear to be projected and of which the apparent dome of the visible sky forms half
"celestial sphere" Antonyms

399 Sentences With "celestial sphere"

How to use celestial sphere in a sentence? Find typical usage patterns (collocations)/phrases/context for "celestial sphere" and check conjugation/comparative form for "celestial sphere". Mastering all the usages of "celestial sphere" from sentence examples published by news publications.

Berlin was also connected to some kind of celestial sphere.
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In order to do this, Cottam had to really study celestial navigation and the celestial sphere.
"Huara" means "star" in Aymara, the Andean language, and Mr. Aravena said he aimed to create a celestial sphere.
The Celestial Sphere Eye Soot in the shade Pyxis is as interstellar as it sounds, and way more long-lasting than you'd think.
In comparison, only 70 galaxies were known to exist in this part of the sky, which covers less than 0.01 percent of the entire celestial sphere.
The arc-like shape of the Milky Way in front of billions of stars and galaxies in the image above is from the exposures being mapped into a celestial sphere.
Then you take off your helmet and emerge from the Kremer Museum, a virtual-reality art gallery of 17th-century Dutch and Flemish paintings, which has been set in an imagined celestial sphere.
Music has the ability to touch the celestial sphere with the tips of its fingers and the awe and wonder we feel is in the desperate temerity of the reach, not just the outcome.
Together, the distance scale and spectroscopy gave scientists the ability to make a star map with much greater detail and three-dimensional perspective: "We were no longer confined to plotting two-dimensional positions on the 'celestial sphere,'" says Lee.
At that moment, the sun's position in the sky is exactly where the ecliptic (the path the planets take as they move through the constellations) crosses the celestial equator (the projection of the Earth's own equator onto the celestial sphere).
At that moment, the sun's position in the sky is exactly where the ecliptic (the plane of the solar system and the path that the planets take as they move through the constellations) crosses the celestial equator (the projection of the Earth's own equator onto the celestial sphere).
I was not expecting them to be nearly so high in the sky, but I should have been, with New York City located at 40.7 degrees north and our most northerly location in South America at 29.3 degrees south, the celestial sphere or visible heavens was tilted fully 70 degrees southward from my mid-northern perspective, revealing an enormous swath of sky forever below the horizon back home.
Mayya marries Abdallah, the son of a wealthy merchant; Asma marries Khalid, a self-obsessed artist for whom the ideal wife is someone who will fall "into the orbit he had marked out, who would always be there but would also always stay just outside, yet without wanting to create her own celestial sphere, her own orbit"; and Khawla, after many years of loyal patience, marries Nasir, her childhood sweetheart, whose idea of marriage involves spending most of his time in Canada with a girlfriend, returning every two years to impregnate his wife.
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The zenith is the "highest" point on the celestial sphere.
Shi Shen and Gan De divided the celestial sphere into 365°, as a tropical year has 365 days. At the time, most ancient astronomers adopted the Babylon division where the celestial sphere is divided by 360°.
The celestial sphere is an imaginary globe of infinite size with the Earth at its center.Bowditch, 2002, p. 234. Positions on the celestial sphere are often expressed using two coordinates: declination and sidereal hour angle, which are similar to latitude and longitude on the surface of the Earth. To define declination, the Earth's equator is projected out to the celestial sphere to construct the celestial equator, and declination is measured in degrees north or south of this celestial equator. Sidereal hour angle is a measurement between 0° and 360°, indicating how far west a body is from an arbitrarily chosen point on the celestial sphere called the First Point of Aries.
The degree of sky polarization as mapped onto the celestial sphere. The degree of polarization. Red is high (approximately 80%) and black is low (0%). Click on the adjacent image to view an animation that represents the degree of polarization as shown on the celestial sphere.
Astronomy provides a method for finding direction at night. All the stars appear to lie on the imaginary Celestial sphere. Because of the rotation of the Earth, the Celestial Sphere appears to rotate around an axis passing through the North and South poles of the Earth. This axis intersects the Celestial Sphere at the North and South Celestial poles, which appear to the observer to lie directly above due North and South respectively on the horizon.
90, at Google books. (a "vanishing circle"). Conversely, observers looking toward the same point on an infinite-radius celestial sphere will be looking along parallel lines, and observers looking toward the same great circle, along parallel planes. On an infinite-radius celestial sphere, all observers see the same things in the same direction.
As Comet ISON moved north on the celestial sphere it would have passed within 2° of Polaris on 8 January.
Earth rotating within a relatively small-radius geocentric celestial sphere. Shown here are stars (white), the ecliptic (red, the circumscription of the Sun's apparent annual track), and the lines of right ascension and circles of declination (cyan) of the equatorial coordinate system. In astronomy and navigation, the celestial sphere is an abstract sphere that has an arbitrarily large radius and is concentric to Earth. All objects in the sky can be conceived as being projected upon the inner surface of the celestial sphere, which may be centered on Earth or the observer.
The plane of Earth's orbit projected in all directions forms the reference plane known as the ecliptic. Here, it is shown projected outward (gray) to the celestial sphere, along with Earth's equator and polar axis (green). The plane of the ecliptic intersects the celestial sphere along a great circle (black), the same circle on which the Sun seems to move as Earth orbits it. The intersections of the ecliptic and the equator on the celestial sphere are the vernal and autumnal equinoxes (red), where the Sun seems to cross the celestial equator.
It is located between Cygnus, Cassiopeia and Andromeda on the northern celestial sphere. The northern part lies on the Milky Way.
The Southern Sky or Southern Hemisphere is, therefore, that half of the celestial sphere that is south of the celestial equator. Even if this one is the ideal projection of the terrestrial equatorial onto the imaginary celestial sphere, the Northern and Southern celestial hemispheres must not be confused with descriptions of the terrestrial hemispheres of Earth itself.
This is because the view from Earth, positioned at the centre of the celestial sphere, is of the gnomonic projection inside of the celestial sphere, whereas the celestial globe is orthographic projection as viewed from the outside. For this reason, celestial globes are often produced in mirror image, so that at least the constellations appear as viewed from earth. Some modern celestial globes address this problem by making the surface of the globe transparent. The stars can then be placed in their proper positions and viewed through the globe, so that the view is of the inside of the celestial sphere.
The Classical planets fit neatly into the theories of Aristotle and Ptolemy, they each are part of a Celestial sphere. The order of the Classical planets is determined by the rate of speed. The Moon moves the fastest and so she is considered to form the first celestial sphere above earth. Everything below the moon is part of the sublunary sphere.
The tape part (created at Bell Labs) can be replaced by silence if desired. Hiemenz, Jack "Augustana College's Major Premiere: Wuorinen's 'Celestial Sphere' Stirs and Fascinates" Musical America, October 1981Sanders, Charles H. "World premiere rocks Centennial" Rock Island Argus April 26, 1981. "Celestial Sphere is complex, effective" Quad-City Times April 28, 1981.McElwain, Bill "Exciting premiere of new oratorio" The Daily Dispach.
Setting circles in conjunction with a star chart or ephemeris allow the telescope to be easily pointed at known objects on the celestial sphere.
Also, linear polarization was measured at 1.25, 2.2, and 3.5 micrometers. During the mission, the instrument could sample half the celestial sphere each day.
However, he is primarily known for his work in astronomy; particularly for his work on determining the positions of objects on the celestial sphere. He remained unmarried and died in 1625. Bayer's star atlas Uranometria Omnium Asterismorum ("Uranometry of all the asterisms") was first published in 1603 in Augsburg and dedicated to two prominent local citizens. This was the first atlas to cover the entire celestial sphere.
The study of relativity is concerned with the Lorentz group generated by the space rotations and hyperbolic rotations.Hestenes 1999, pp. 580–588. Whereas rotations, in physics and astronomy, correspond to rotations of celestial sphere as a 2-sphere in the Euclidean 3-space, Lorentz transformations from induce conformal transformations of the celestial sphere. It is a broader class of the sphere transformations known as Möbius transformations.
This was an early and convenient method to use if you had access to an astrolabe as many astrologers and mathematicians of the time would have had. The method involved copying the projections of the celestial sphere onto a plane surface. A vertical line was drawn with a line at the angle of the latitude drawn on the bisection of the vertical with the celestial sphere.
Criteria in the choice of stars includes their distribution across the celestial sphere, brightness, and ease of identification.Wright and Whitney, 1992, p. 273. Information for another 115 stars, known as "tabulated stars", is also available to the navigator. This list provides information on the name, approximate position in the celestial sphere, and apparent magnitude of the 58 selected stars in tabular form and by star charts.
Muslim scholars invented and refined a number of scientific instruments in mathematical geography and cartography. These included the astrolabe, quadrant, gnomon, celestial sphere, sundial, and compass.
Its north pole star is currently Omicron Draconis.note: due to axial precession, the lunar pole describes a small circle on the celestial sphere every 18.6 years.
Orange = equinoctial colure Blue = solstitial colure G = equinoctial colure H = solstitial colure Colure, in astronomy, is either of the two principal meridians of the celestial sphere.
If centered on the observer, half of the sphere would resemble a hemispherical screen over the observing location. The celestial sphere is a practical tool for spherical astronomy, allowing astronomers to specify the apparent positions of objects in the sky if their distances are unknown or irrelevant. In the equatorial coordinate system, the celestial equator divides the celestial sphere into two halves: the northern and southern celestial hemispheres.
These concepts are important for understanding celestial coordinate systems, frameworks for measuring the positions of objects in the sky. Certain reference lines and planes on Earth, when projected onto the celestial sphere, form the bases of the reference systems. These include the Earth's equator, axis, and orbit. At their intersections with the celestial sphere, these form the celestial equator, the north and south celestial poles, and the ecliptic, respectively.
Unlike the fixed stars, the Sun changes its position on the celestial sphere, being - on north hemisphere - at a positive declination in spring and summer, and at a negative declination in autumn and winter, and having exactly zero declination (i.e., being on the celestial equator) at the equinoxes. The Sun's celestial longitude also varies, changing by one complete revolution per year. The path of the Sun on the celestial sphere is called the ecliptic.
Spherical coordinates, projected on the celestial sphere, are analogous to the geographic coordinate system used on the surface of Earth. These differ in their choice of fundamental plane, which divides the celestial sphere into two equal hemispheres along a great circle. Rectangular coordinates, in appropriate units, are simply the cartesian equivalent of the spherical coordinates, with the same fundamental () plane and primary (-axis) direction. Each coordinate system is named after its choice of fundamental plane.
Celestial globe by Jost Bürgi (1594) A celestial sphere can also refer to a physical model of the celestial sphere or celestial globe. Such globes map the constellations on the outside of a sphere, resulting in a mirror image of the constellations as seen from Earth. The oldest surviving example of such an artifact is the globe of the Farnese Atlas sculpture, a 2nd-century copy of an older (Hellenistic period, ca. 120 BCE) work.
The sky above the clouds The sky (also sometimes called celestial dome) is everything that lies above the surface of the Earth, including the atmosphere and outer space. In the field of astronomy, the sky is also called the celestial sphere. This is an abstract sphere, concentric to the Earth, on which the Sun, Moon, planets, and stars appear to be drifting. The celestial sphere is conventionally divided into designated areas called constellations.
Johannes Hevelius's depiction of Andromeda, from the 1690 edition of his Uranographia. As was conventional for celestial atlases of the time, the constellation is a mirror image of modern maps as it was drawn from a perspective outside the celestial sphere. Andromeda as depicted in Urania's Mirror, a set of constellation cards published in London c. 1825, showing the constellation from the inside of the celestial sphere Andromeda depicted in an early scientific manuscript, c.
The ancients assumed the literal truth of stars attached to a celestial sphere, revolving about the Earth in one day, and a fixed Earth. , art. 2, p. 5, at Google books.
This is symmetrical between the North and South hemispheres. The right one represents the angle at the zenith between the solar direction and the pointing. It thus rotates around the celestial sphere.
Atlas was laid out in 1884, and named after Atlas, a deity who held up the celestial sphere. A post office was established at Atlas in 1884, and remained in operation until 1943.
14 which appears to rotate westward overhead; meanwhile, Earth underfoot seems to remain still. For purposes of spherical astronomy, which is concerned only with the directions to celestial objects, it makes no difference if this is actually the case or if it is Earth that is rotating while the celestial sphere is stationary. The celestial sphere can be considered to be infinite in radius. This means any point within it, including that occupied by the observer, can be considered the center.
His system still upheld the tradition of a celestial sphere holding the fixed stars. Kepler also provided a model of the cosmos in his 1596 book Mysterium Cosmopgraphicum which pictures an image, labelling one celestial sphere, in Latin, "sphaera stellar fixar," or a sphere of fixed stars. The studies of the heavens were revolutionized with the invention of the telescope. First developed in 1608, the development of telescopes was widely publicized, and Galileo heard and made a telescope for himself.
It has a relatively high proper motion across the celestial sphere, suggesting that it has a peculiar velocity roughly three times higher than its neighbors. Nu Hydrae was a later designation of 4 Crateris.
The equinoctial colure is the meridian or great circle of the celestial sphere which passes through the celestial poles and the two equinoxes: the first point of Aries and the first point of Libra.
Two kinds of year are relevant to understanding his work. The tropical year is the length of time that the Sun, as viewed from the Earth, takes to return to the same position along the ecliptic (its path among the stars on the celestial sphere). The sidereal year is the length of time that the Sun takes to return to the same position with respect to the stars of the celestial sphere. Precession causes the stars to change their longitude slightly each year, so the sidereal year is longer than the tropical year.
For some objects, this is over-simplified. Objects which are relatively near to the observer (for instance, the Moon) will seem to change position against the distant celestial sphere if the observer moves far enough, say, from one side of planet Earth to the other. This effect, known as parallax, can be represented as a small offset from a mean position. The celestial sphere can be considered to be centered at the Earth's center, the Sun's center, or any other convenient location, and offsets from positions referred to these centers can be calculated.
The Earth in its orbit around the Sun causes the Sun to appear on the celestial sphere moving over the ecliptic (red), which is tilted on the equator (blue). The Zodiac is a group of 12 constellations: Leo, Virgo, Libra, Scorpius, Sagittarius, Capricornus, Aquarius, Pisces, Aries, Taurus, Gemini, and Cancer. Some version of these constellations are found in traditions around the world, for this band around the celestial sphere includes the ecliptic, the apparent path of the sun through the year. These constellations therefore are all associated with zodiac signs.
As seen from the orbiting Earth, the Sun appears to move with respect to the fixed stars, and the ecliptic is the yearly path the Sun follows on the celestial sphere. This process repeats itself in a cycle lasting a little over 365 days. The ecliptic is the plane of Earth's orbit around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the background of stars.
The astrolabe, an instrument that has its origins in Hellenistic astronomy, is a predecessor of the modern planisphere. The term planisphere contrasts with armillary sphere, where the celestial sphere is represented by a three-dimensional framework of rings.
The celestial sphere has been divided into 88 constellations. The IAU constellations are areas of the sky. Each of these contains remarkable X-ray sources. Some of them are galaxies or black holes at the centers of galaxies.
Auriga constellation. Elnath is the star at the bottom of the ring. The galactic anticenter is a direction in space directly opposite to the Galactic Center, as viewed from Earth. This direction corresponds to a point on the celestial sphere.
In terms of the total celestial sphere, the Sun and the Moon subtend fractional areas of 0.000542% (5.42 ppm) and 0.000531% (5.31 ppm), respectively. On average, the Sun is larger in the sky than the Moon even though it is much, much farther away.
Locating an object on the celestial sphere using setting circles is similar to finding a location on a terrestrial map using latitude and longitude. Sometimes the RA setting circle has two scales on it: one for the Northern Hemisphere and one for the Southern.
It is drawn from the sun through the zenith to the other side of the celestial sphere where the "anti-sun" would be. This is also the effective East-Zenith- West plane. The q input. Red is high (approximately 80%) and black is low (0%).
From the September equinox to the March equinox, the Sun rises within 23.44° south of due east and sets within 23.44° south of due west. The Sun's path lies entirely in the northern half of the celestial sphere from the March equinox to the September equinox, but lies entirely in the southern half of the celestial sphere from the September equinox to the March equinox. On the equinoxes, the equatorial Sun culminates at the zenith, passing directly overhead at solar noon. The fact that the equatorial Sun is always so close to the zenith at solar noon explains why the tropical zone contains the warmest regions on the planet overall.
Because of a phenomenon known as the precession of the equinoxes, the poles trace out circles on the celestial sphere, with a period of about 25,700 years. The Earth's axis is also subject to other complex motions which cause the celestial poles to shift slightly over cycles of varying lengths (see nutation, polar motion and axial tilt). Finally, over very long periods the positions of the stars themselves change, because of the stars' proper motions. An analogous concept applies to other planets: a planet's celestial poles are the points in the sky where the projection of the planet's axis of rotation intersects the celestial sphere.
In astronomy and celestial navigation, the hour angle is one of the coordinates used in the equatorial coordinate system to give the direction of a point on the celestial sphere. The hour angle of a point is the angle between two planes: one containing Earth's axis and the zenith (the meridian plane), and the other containing Earth's axis and the given point (the hour circle passing through the point). The hour angle is indicated by an orange arrow on the celestial equator plane. The arrow ends at the hour circle of an orange dot indicating the apparent place of an astronomical object on the celestial sphere.
In the context of astronomical discussions or writing about celestial cartography, this celestial hemisphere may also simply then be referred to as the Northern Hemisphere. For the purpose of celestial mapping, astronomers may conceive the sky as the inside of a sphere divided into two halves by the celestial equator. The Northern Sky or Northern Hemisphere is therefore the half of the celestial sphere that is north of the celestial equator. Even if this geocentric model is the ideal projection of the terrestrial equator onto the imaginary celestial sphere, the northern and southern celestial hemispheres is not to be confused with descriptions of the terrestrial hemispheres of Earth itself.
Replogle makes metal globes, light-up globes (in glass [vintage], cardboard, and plastic), inflatable plastic globes, transparent globes, a cube-shaped globe, and a variety of globe stands. In addition to globes of Earth, Replogle also makes globes of Venus, Mars, the Moon, and the celestial sphere.
8Me Gott eij egen firmament bwe Ianweron. Ma antsiemerin ma antsioran ar eke ũrõr karabũmit ibũm. It is notable that the Nauruan vocabulary contains a few German loanwords (e.g. Gott, "God"; and Firmament, "celestial sphere"), which is traced back to the strong influence of German missionaries.
Hevelius' Uranographia. Ursa Major's cover is derived from Uranographia, a 17th-century drawing by Johannes Hevelius. The view is mirrored following the tradition of celestial globes, showing the celestial sphere in a view from "outside", with the drawing mirrored to match the view through a telescope.
It was said that for a long time the Hanau family possessed a silver "terrestrial and celestial sphere" that Philipp had manufactured himself. In his last years, Philipp V was sick. He died in 1599 during a visit to the spa in Bad Niederbronn. He was buried in Lichtenberg.
The celestial sphere has been divided into 88 constellations. The International Astronomical Union (IAU) constellations are areas of the sky. Each of these contains remarkable X-ray sources. Some of them have been identified from astrophysical modeling to be galaxies or black holes at the centers of galaxies.
Straight Lines, 'Uncurved Lines', and Helmholtz's 'Great Circles on the Celestial Sphere'. Perception, 36(9), 1275-1289. The retina also has variable sensitivity across its wider-than-180° horizontal field-of-view and ranging in resolution in peripheral or foveal vision.Cooper, E., Piazza, E., and Banks, M. (2012).
Celestial Sphere, 18th century. Brooklyn Museum. Because astronomical objects are at such remote distances, casual observation of the sky offers no information on their actual distances. All celestial objects seem equally far away, as if fixed onto the inside of a sphere with a large but unknown radius, , p.
In this article the word describes the representation of the star-filled celestial sphere on the plane. The first star chart to have the name "planisphere" was made in 1624 by Jacob Bartsch. Bartsch was the son-in-law of Johannes Kepler, discoverer of Kepler's laws of planetary motion.
LEDA 74886 is located in the celestial sphere at a right ascension (\alpha) of , and a declination (\delta) of (J2000). It is located within the Galactic corona of NGC 1407, a massive spherical galaxy which is located approximately 163,000 ly (50 kpc) to the northwest of LEDA 74886.
Anaximander was the first astronomer to consider the Sun as a huge mass, and consequently, to realize how far from Earth it might be, and the first to present a system where the celestial bodies turned at different distances. Furthermore, according to Diogenes Laertius (II, 2), he built a celestial sphere. This invention undoubtedly made him the first to realize the obliquity of the Zodiac as the Roman philosopher Pliny the Elder reports in Natural History (II, 8). It is a little early to use the term ecliptic, but his knowledge and work on astronomy confirm that he must have observed the inclination of the celestial sphere in relation to the plane of the Earth to explain the seasons.
In the center of one large mosaic is the Sun god, Helios, sitting in his chariot holding the celestial sphere and a whip. Nine of the 12 signs of the zodiac survived intact. Another panel shows a Torah ark flanked by two the seven-branched menorahs and other Jewish ritual objects.
Earth-centered ecliptic coordinates as seen from outside the celestial sphere. Ecliptic longitude (red) is measured along the ecliptic from the vernal equinox. Ecliptic latitude (yellow) is measured perpendicular to the ecliptic. A full globe is shown here, although high-latitude coordinates are seldom seen except for certain comets and asteroids.
The armillary sphere has three sets of rings that represent the celestial sphere. The first group contains fixed meridian, horizon, and equatorial rings. The second group contains ecliptic, solstitial, and equinoctial rings that turn as a unit. The inner group contains one meridian ring that moves around the celestial pole.
The Celestial Sphere, the Wheel of Fortune, and Fate in the Gazels of Naili and Baki, Walter Feldman, International Journal of Middle East Studies, Vol. 28, No. 2 (May, 1996), 197.Walter G. Andrews, Najaat Black, Mehmet Kalpaklı, Ottoman lyric poetry: An Anthology, (University of Washington Press, 2006), 211. Ḥurūfī poet.
The Indian mathematician Aryabhata (AD 476–550) was a pioneer of mathematical astronomy. He describes the earth as being spherical and that it rotates on its axis, among other things in his work Āryabhaṭīya. Aryabhatiya is divided into four sections. Gitika, Ganitha (mathematics), Kalakriya (reckoning of time) and Gola (celestial sphere).
The Globe Museum () is a museum in the Palais Mollard, Vienna, Austria, part of the Austrian National Library. It was opened in 1956, and is the only public museum in the world devoted to globes, being three-dimensional models of Earth or other celestial bodies, or spherical representations of the celestial sphere.
The word "Uranometria" derives from Urania, Muse of the heavens and "uranos" (oυρανός) the Greek word for sky / heavens. A literal translation of "Uranometria" is "Measuring the Heavens" (to be compared with "Geometry"-"Geometria" in Greek, literally translated to "Measuring the Earth"). It was the first atlas to cover the entire celestial sphere.
In other cases, the combination of cross and nimbus symbolized the presence of Christ throughout the cosmos, with the nimbus representing the celestial sphere. Notable early examples include the cosmological ringed cross in the 5th-century Mausoleum of Galla Placidia, and the 6th-century Crux Gemmata in the Basilica of Sant'Apollinare in Classe.
The path of the Sun over the celestial sphere through the course of the day for an observer at 56°N latitude. The Sun's path changes with its declination during the year. The intersections of the curves with the horizontal axis show azimuths in degrees from North where the Sun rises and sets.
The poles of astronomical bodies are determined based on their axis of rotation in relation to the celestial poles of the celestial sphere. Astronomical bodies include stars, planets, dwarf planets and small Solar System bodies such as comets and minor planets (i.e. asteroids), as well as natural satellites and minor-planet moons.
Saint Hyacinth healing the Blind Twins. Disputa of the Eucharist Celestial sphere of the Disputa', often mistaken for the Sputnik satellite' Ventura di Archangelo Salimbeni (also later called Bevilacqua; 20 January 1568 - 1613) was an Italian Counter-Maniera painter and printmaker highly influenced by the vaghezza and sensual reform of Federico Barocci.
Finally, it may be the case that more than one of these factors has come into play. According to that theory, the number is approximately 365 because of the apparent movement of the sun against the celestial sphere, and that it was rounded to 360 for some of the mathematical reasons cited above.
Solrad 10, also known Explorer 44, NRL-PL 165 and Explorer SE-C, was one of the SOLRAD series designed to provide continuous coverage of wavelength and intensity changes in solar radiation in the UV, soft and hard X-ray regions. The satellite also mapped the celestial sphere using a high-sensitivity X-ray detector.
An illustration from al- Biruni's astronomical works, explains the different phases of the moon, with respect to the position of the sun. The notion of satellite systems pre-dates history. The Moon was known by the earliest humans. The earliest models of astronomy were based around celestial bodies (or a "celestial sphere") orbiting the Earth.
In astrology, the Equatorial Ascendant, or the East Point, is the sign and degree rising over the Eastern Horizon at the Earth's equator at any given time. In the celestial sphere it corresponds to the intersection of the ecliptic with a great circle containing the celestial poles and the East point of the horizon.
Cartesian coordinates are used. The x–y plane coincides with the equatorial plane of Earth. The x-axis is permanently fixed in a direction relative to the celestial sphere, which does not rotate as Earth does. The z-axis lies at a 90° angle to the equatorial plane and extends through the North Pole.
Diagram showing the relationship between the zenith, the nadir, and different types of horizon. Note that the zenith is opposite the nadir. The zenith is an imaginary point directly "above" a particular location, on the imaginary celestial sphere. "Above" means in the vertical direction (plumb line) opposite to the gravity direction at that location (nadir).
The modelGeographica II.5.3. divided the universe into a celestial and an earthly sphere pierced by the same poles. Each of the spheres were divided into zones (zonai) by circles (kukloi) in planes at right angles to the poles. The zones of the celestial sphere repeated on a larger scale those of the terrestrial sphere.
Furthermore, distant stars and galaxies move even slower in the sky than comparatively closer ones. People in many cultures have imagined that the stars form pictures in the sky called constellations. In Ancient Greek astronomy, the fixed stars were believed to exist on a giant celestial sphere, or firmament, that revolves daily around Earth.
Reproduction of the Suzhou star chart (13th century) Traditional Chinese astronomy has a system of dividing the celestial sphere into asterisms or constellations, known as "officials" (Chinese xīng guān). literally translates to "star official". The English translation "officials" is used in Hsing-chih T'ien. and Will Carl Rufus, The Soochow astronomical chart, Ann Arbor : Univ.
However, between November 1 and 10, the two streams equalize. The brightest member of this constellation is Aldebaran, an orange-hued, spectral class K5 III giant star. Its name derives from ' ', Arabic for "the follower", probably from the fact that it follows the Pleiades during the nightly motion of the celestial sphere across the sky.
Dillon (1998), 378. However, some scholars also point out that Zhang's writing lacks concrete scientific theories.Jin, Fan, and Liu (1996), 170. Comparing Zhang with his contemporary, Ptolemy (83–161) of Roman Egypt, Jin Guantao, Fan Hongye, and Liu Qingfeng state: ::Based on the theories of his predecessors, Zhang Heng systematically developed the celestial sphere theory.
The equation of time is the east or west component of the analemma, a curve representing the angular offset of the Sun from its mean position on the celestial sphere as viewed from Earth. The equation of time values for each day of the year, compiled by astronomical observatories, were widely listed in almanacs and ephemerides.
The Hercules Family is a group of constellations connected mainly by their adjacency on the celestial sphere. It is Menzel's largest grouping, and extends from declination +60° to −70°, mostly in the western hemisphere. It includes Hercules, Sagitta, Aquila, Lyra, Cygnus, Vulpecula, Hydra, Sextans, Crater, Corvus, Ophiuchus, Serpens, Scutum, Centaurus, Lupus, Corona Australis, Ara, Triangulum Australe, and Crux.
The idea for a celestial sphere was approved in 1944, and the sculpture was completed in 1948.Aero Memorial, Interactive map, accessed March 1, 2013. Aero Memorial was dedicated on June 1, 1950. Aero Memorial is one of 51 sculptures included in the Association for Public Art's Museum Without Walls interpretive audio program for Philadelphia's outdoor sculpture.
Sale concluded that the earlier seat of the gods was the actual Mount Olympus, from which the epic tradition by the time of Homer had transported them to the sky, ouranos. By the sixth century, when a "heavenly Aphrodite" (Aphrodite Urania) was to be distinguished from the "common Aphrodite of the people", ouranos signifies purely the celestial sphere itself.
In a foxhole, a grenade sump is a deeper hole dug inside the foxhole into which live grenades can be kicked to minimize damage from the explosion. In medieval cosmology, the sump was the center of the cosmos, where the dregs and filth descended, with the celestial sphere far exalted above the world of fallen man.
Apart from writing he also created maps and earth and celestial sphere globes. He also attempted to create a paper mill, but he failed. He set up a lithography place in Athens. He estimated the amount of the books he had printed to be about 25,000 volumes, covering a range of subjects: medicine, geography, history, morality, grammar.
73-76), which includes the quote about "no serious seventeenth century astronomer" on p. 76; Campbell 1921 (p. 848); Catholic Encyclopedia: Giovanni Battista Riccioli. Within its two volumes were ten "books" covering every subject within astronomy and related to astronomy at the time: #the celestial sphere and subjects such as celestial motions, the equator, ecliptic, zodiac, etc.
Liddell, Henry George and Scott, Robert. "Arktos." A Greek-English Lexicon. Perseus Digital Library. The name refers either to the constellation Ursa Major, the "Great Bear", which is prominent in the northern portion of the celestial sphere, or to the constellation Ursa Minor, the "Little Bear", which contains Polaris, the Pole Star, also known as the North Star.
It remains zero around a circle based on the sun and the zenith. As it passes the zenith it rotates toward the south and repeats the same pattern until sunset. The second image to the right represents the u input mapped onto the celestial sphere. The u stokes parameter changes signs depending on which quadrant it is in.
In astronomy, an equinox is either of two places on the celestial sphere at which the ecliptic intersects the celestial equator. Although there are two intersections of the ecliptic with the celestial equator, by convention, the equinox associated with the Sun's ascending node is used as the origin of celestial coordinate systems and referred to simply as "the equinox". In contrast to the common usage of spring/vernal and autumnal equinoxes, the celestial coordinate system equinox is a direction in space rather than a moment in time. In a cycle of about 25,700 years, the equinox moves westward with respect to the celestial sphere because of perturbing forces; therefore, in order to define a coordinate system, it is necessary to specify the date for which the equinox is chosen.
Cetus dominates this card from Urania's Mirror (1825) as if looking up towards the celestial sphere (east is left of frame). Uses the modern custom: celestial maps to be held skywards while facing south. An alike depiction from Celestial Atlas (A. Jamieson) (1822) Cetus may have originally been associated with a whale, which would have had mythic status amongst Mesopotamian cultures.
Earth's axial tilt (obliquity) is currently about 23.4°. Earth's orbital plane is known as the ecliptic plane, and Earth's tilt is known to astronomers as the obliquity of the ecliptic, being the angle between the ecliptic and the celestial equator on the celestial sphere. It is denoted by the Greek letter ε. Earth currently has an axial tilt of about 23.44°.
Uranopolis or Ouranopolis () was a city in the Chalcidice in ancient Macedonia, allegedly founded by Alexarchus, brother of king Cassander of Macedonia.Athen. 3.98; Uranopolis was the site of a mint in the Kingdom of Thrace. Coins of Uranopolis are known for displaying Athena or the Muse Aphrodite Urania, the muse of astronomy, sitting on a globe. The globe represents the Celestial Sphere.
The location of stars, planets, and other similarly distant objects is usually expressed in the following parameters, one for each of the three spatial dimensions: their declination, right ascension (epoch-fixed hour angle), and distance. These are as located at the vernal equinox for the epoch (e.g. J2000) stated. A meridian on the celestial sphere matches an hour circle at any time.
Around 1025, he describes a polar equi-azimuthal equidistant projection of the celestial sphere. However, this type of projection had been used in ancient Egyptian star-maps and was not to be fully developed until the 15 and 16th centuries. In the early 10th century, Abū Zayd al-Balkhī, originally from Balkh, founded the "Balkhī school" of terrestrial mapping in Baghdad.
It has a relatively high proper motion, advancing across the celestial sphere at the rate of 0.298 arc seconds per annum. The star HD 8574 is named Bélénos. The name was selected in the NameExoWorlds campaign by France, during the 100th anniversary of the IAU. Bélénos was the god of light, of the Sun, and of health in Gaulish mythology.
The system has a relatively high rate of proper motion, traversing the celestial sphere at the rate of . This is a single- lined spectroscopic binary with an orbital period of and an eccentricity of 0.88. The a sin i value for the primary is , where a is the semimajor axis and i is the orbital inclination. The inclination is estimated to be 104°.
The solstitial colure is the meridian or great circle of the celestial sphere which passes through the poles and the two solstices: the first point of Cancer and the first point of Capricorn. There are several stars closely aligned with the solstitial colure: Pi Herculis, Delta Aurigae, and Theta Scorpii. This makes the solstitial colure point towards the North Celestial Pole and Polaris.
" The poem reads as follows: "Inner time is limitless – from past lives I can no longer remember, only feel. Time flows, and around me a continuum moves and swirls, engulfing me, and moves majestically beyond my inner sight or imagination. This time is immense, a celestial sphere yet it does not forget me, does not neglect me. It embraces me.
Representing of Shizuoka Prefecture, is the reigning Gunpla Battle World Champion and the dominant national team for six years in a row. The school was incorporated from a previous Gunpla academy that was owned by PPSE. Celestial Sphere gets its name from Celestial Being of Mobile Suit Gundam 00. ; : :Gunpla: GN-9999 Transient Gundam :The team leader who is Allan Adams' nephew.
Thus the degree of polarization as well as its corresponding angle clearly shifts around the horizon. When the sun is located at the zenith the horizon represents a constant degree of polarization. The corresponding polarization angle still shifts with different directions toward the zenith from different points. The video to the right represents the polarization angle mapped onto the celestial sphere.
The mathematician Claudius Ptolemy 'the Alexandrian' as imagined by a 16th- century artist The Planisphaerium is a work by Ptolemy. The title can be translated as "celestial plane" or "star chart". In this work Ptolemy explored the mathematics of mapping figures inscribed in the celestial sphere onto a plane by what is now known as stereographic projection. This method of projection preserves the properties of circles.
The field of astronomy, especially as it relates to mapping the positions of stars and planets on the celestial sphere and describing the relationship between movements of celestial bodies, have served as an important source of geometric problems throughout history. Riemannian geometry and pseudo-Riemannian geometry are used in general relativity. String theory makes use of several variants of geometry, as does quantum information theory.
A near-equatorial orbit is an orbit that lies close to the equatorial plane of the object orbited. Such an orbit has an inclination near 0°. On Earth, such orbits lie on the celestial equator, the great circle of the imaginary celestial sphere on the same plane as the equator of Earth. A geostationary orbit is a particular type of equatorial orbit, one which is geosynchronous.
It contains two stars with known planets, including 55 Cancri, which has five: one super-earth and four gas giants, one of which is in the habitable zone and as such has expected temperatures similar to Earth. At the (angular) heart of this sector of our celestial sphere is Praesepe (Messier 44), one of the closest open clusters to Earth and a popular target for amateur astronomers.
It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.188 arc seconds per annum. 20 Arietis is receding from the Earth with a heliocentric radial velocity of +25 km/s. Gray et al. (2001) gave the stellar classification of 20 Arietis as F6 III-IV, matching an F-type star with spectral traits intermediate between a giant and a subgiant star.
The declination symbol , (lower case "delta", abbreviated DEC) measures the angular distance of an object perpendicular to the celestial equator, positive to the north, negative to the south. For example, the north celestial pole has a declination of +90°. The origin for declination is the celestial equator, which is the projection of the Earth's equator onto the celestial sphere. Declination is analogous to terrestrial latitude.
In celestial navigation, the convention is to measure in degrees westward from the prime meridian (Greenwich hour angle, GHA), from the local meridian (local hour angle, LHA) or from the first point of Aries (sidereal hour angle, SHA). The hour angle is paired with the declination to fully specify the location of a point on the celestial sphere in the equatorial coordinate system.Explanatory Supplement (1992), p. 724.
How right ascension got its name. Ancient astronomy was very concerned with the rise and set of celestial objects. The ascension was the point on the celestial equator (red) which rose or set at the same time as an object (green) on the celestial sphere. As seen from the equator, both were on a great circle from pole to pole (left, sphaera recta or right sphere).
Setting circles consist of two graduated disks attached to the axes – right ascension (RA) and declination (DEC) – of an equatorial mount. The RA disk is graduated into hours, minutes, and seconds. The DEC disk is graduated into degrees, arcminutes, and arcseconds. Since the RA coordinates are fixed onto the celestial sphere, the RA disk is usually driven by a clock mechanism in sync with sidereal time.
It was ESRO's first 3-axis stabilized satellite, with one axis pointing to the Sun to within ±5°. The optical axis was maintained perpendicular to the solar pointing axis and to the orbital plane. It scanned the entire celestial sphere every 6 months, with a great circle being scanned every satellite revolution. After about 2 months of operation, both of the satellite's tape recorders failed.
The gnomonic projection is used extensively in photography, where it is called rectilinear projection. Because they are equivalent, the same viewer used for photographic panoramas can be used to render gnomonic maps . The gnomonic projection is used in astronomy where the tangent point is centered on the object of interest. The sphere being projected in this case is the celestial sphere, R = 1, and not the surface of the Earth.
56 Cygni is a single star in the northern constellation of Cygnus, located 135 light years from Earth. It is visible to the naked eye as a white-hued star with an apparent visual magnitude of 5.06. The star is moving closer to the Earth with a heliocentric radial velocity of −21.5. It has a relatively high proper motion, traversing the celestial sphere at an angular rate of /yr.
It has a relatively high proper motion, traversing the celestial sphere at the rate of per year. This is an ordinary G-type main-sequence star with a stellar classification of G0 V. It has some similarities to the Sun, and thus is considered a solar analog. Brewer et al. (2016) estimate the star has 1.3 times the mass of the Sun and 1.44 times the Sun's radius.
This cloud covers an angular area of on the celestial sphere. It consists of two major regions of dense gas and dust. The first contains a star-forming cloud (L1688) and two filaments (L1709 and L1755), while the second has a star-forming region (L1689) and a filament (L1712–L1729). These filaments extend up to 10–17.5 parsecs in length and can be as narrow as 0.24 parsecs in width.
Against Tycho: The final part of the Discourse is an assault on Tycho and his arguments. First he points out the implausibility of there being a celestial sphere devoted to comets, as they move in different directions and at different speeds. Next he argues from the apparent motion and speed of comets that they are more likely to travel in straight lines than in a circle, as Tycho had suggested.
A rainbow is always centred around the antisolar point, which coincides with the shadow of the observer's head, seen here at the bottom of the frame. haloes, as viewed from a plane. The antisolar point is the abstract point on the celestial sphere directly opposite the Sun from an observer's perspective. This means that the antisolar point lies above the horizon when the Sun is below it, and vice versa.
The directions north and south on the celestial sphere are in the sense toward the north celestial pole and toward the south celestial pole. East is the direction toward which Earth rotates, west is opposite that. The crossing from south to north is known as the vernal equinox, also known as the first point of Aries and the ascending node of the ecliptic on the celestial equator.Astronomical Almanac 2010, p.
The Physics department of the UPRM College of Arts and Sciences currently run the Planetarium and its Astronomical Observatory. Both were inaugurated in 1973 and have continued working and functioning uninterruptedly since. The Planetarium is a projection room whose hemispherical screen simulates the Celestial sphere. In this screen one can observe close to 4,000 stars, simulating the sky as seen from anywhere in the world and at any time of year.
This is the apparent orbit, the projection of the orbit of the two stars onto the celestial sphere; the true orbit can be computed from it.p. 53–67, Observing and Measuring Double Stars, Bob Argyle, ed., London: Springer-Verlag, 2004, . Although it is expected that the majority of catalogued visual doubles are visual binaries, orbits have been computed for only a few thousand of the over 100,000 known visual double stars.
Beta Ceti (β Ceti, abbreviated Beta Cet, β Cet), also named Diphda , is the brightest star in the constellation of Cetus. Although designated 'beta', it is actually brighter than the 'alpha' star in the constellation (Alpha Ceti). This orange giant is easy to identify due to its location in an otherwise dark section of the celestial sphere. Based on parallax measurements, it lies at an estimated distance of from the Sun.
Needham (1986), Volume 3, 227. The theory posited by Zhang and Jing was supported by later pre-modern scientists such as Shen Kuo (1031–1095), who expanded on the reasoning of why the Sun and Moon were spherical.Needham (1986), Volume 3, 415–416. The theory of the celestial sphere surrounding a flat, square Earth was later criticized by the Jin-dynasty scholar-official Yu Xi (fl. 307-345).
14 Canis Minoris, also known as HD 65345, is a single star in the equatorial constellation of Canis Minor. It is faintly visible to the naked eye with an apparent visual magnitude of +5.30. The distance to this star, as determined from an annual parallax shift of , is approximately 242 light years. 14 CMI has a relatively large proper motion, traversing the celestial sphere at the rate of .
And each "emanates" downwards the body and soul of its own celestial sphere, and also the intellect at the next lowest level. The active intellect, as in Alfarabi, is the last in the chain. Avicenna sees active intellect as the cause not only of intelligible thought and the forms in the "sublunar" world we people live, but also the matter. (In other words, three effects.)Davidson ch. 4.
Hyperbolas may be seen in many sundials. On any given day, the sun revolves in a circle on the celestial sphere, and its rays striking the point on a sundial traces out a cone of light. The intersection of this cone with the horizontal plane of the ground forms a conic section. At most populated latitudes and at most times of the year, this conic section is a hyperbola.
Earth rotating within the celestial sphere. In this view, the Southern Celestial Hemisphere is below the celestial equator, the middle parallel (in cyan). In the context of astronomical discussions or writing about celestial mapping, it may also simply then be referred to as the Southern Hemisphere. For the purpose of celestial mapping, the sky is considered by astronomers as the inside of a sphere divided in two halves by the celestial equator.
49 Persei is a star in the northern constellation of Perseus. It is just visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 6.09. Based upon parallax measurements, this star is located around away from the Sun, but is drifting closer with a radial velocity of −44 km/s. It has a relatively large proper motion, traversing the celestial sphere at a rate of ·yr−1.
Gugler later bought a 5-foot (1.52 m) diameter glass sphere etched with the constellations. He lent this to Manship, who created multiple sculptures inspired by it.Sotheby's, "Celestial Sphere", American Paintings, 29 November 2006, Lot 22. For what became the Aero Memorial (plaster 1933), Manship modeled Zodiac figures in clay directly atop the glass sphere, then cast them in plaster and bronze.Harry Rand, Paul Manship (Washington, D.C.: Smithsonian Institution, 1989), pp. 124–27.
HD 211415 is a double star in the constellation Grus. With an apparent visual magnitude of 5.33, it is visible to the naked eye. The annual parallax shift is 72.54 mas, which yields a distance estimate of 45 light years. It has a relatively high proper motion, traversing the celestial sphere at the rate of 93.4 mas per year, and is moving closer to the Sun with a radial velocity of −13 km/s.
It has a relatively high rate of proper motion, traversing the celestial sphere at the rate of per year. The primary, designated component A, is an F-type main-sequence star with a stellar classification of F7V. It is an estimated 2.51 billion years old and is spinning with a projected rotational velocity of 9.1 km/s. The star has 1.21 times the mass of the Sun and 1.26 times the Sun's radius.
The basic elements of Ptolemaic astronomy, showing a planet on an epicycle with an eccentric deferent and an equant point. The Green shaded area is the celestial sphere which the planet occupies. Although the basic tenets of Greek geocentrism were established by the time of Aristotle, the details of his system did not become standard. The Ptolemaic system, developed by the Hellenistic astronomer Claudius Ptolemaeus in the 2nd century AD finally standardised geocentrism.
The geocentric (Ptolemaic) model of the solar system is still of interest to planetarium makers, as, for technical reasons, a Ptolemaic-type motion for the planet light apparatus has some advantages over a Copernican- type motion. The celestial sphere, still used for teaching purposes and sometimes for navigation, is also based on a geocentric system which in effect ignores parallax. However this effect is negligible at the scale of accuracy that applies to a planetarium.
6 Lyncis is a star in the northern constellation of Lynx, located approximately 179 light years from Earth. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.86. This object is moving away from the Earth with a heliocentric radial velocity of +40 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.341 arc seconds per annum.
In the centre of the starry realm below is a celestial sphere with the signs of the zodiac. On the left site the sun-god, his body marked with the signs of the zodiac that govern the respective parts of the body. He carries a caduceus, a token of Hermes, topped with the symbol of an eye, that may denote hermetic wisdom. His feet rest upon the double-headed eagle of the Habsburgs.
Valérian steps into the machine and two images of him are produced – one of him as a boy and one as an old man. The three Valérians leave Urs and make for the Northern Desert. After many days of searching they at last find the Star Gate, a vast celestial sphere lying in a black lake. The older Valérian reveals that the letters inscribed on the device resemble those seen on Earth in Tibet.
The star is moving further from the Sun with a radial velocity of +26.6 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.237 arc seconds per year. The combination of these movements indicate this star is a member of the Hyades supercluster. Li et al. (2000) categorized this as an F-type main-sequence star with a stellar classification of F5 V(e).
45 Boötis is a single star located 63 light years away from the Sun in the northern constellation of Boötes. It has the Bayer designation c Boötis; 45 Boötis is the Flamsteed designation. This body is visible to the naked eye as a faint, yellow-white hued star with an apparent visual magnitude of 4.93. It has a relatively high proper motion, traversing the celestial sphere at the rate of per year.
Einstein became the first to calculate the correct value for light bending. The first observation of light deflection was performed by noting the change in position of stars as they passed near the Sun on the celestial sphere. The observations were performed in 1919 by Arthur Eddington, Frank Watson Dyson, and their collaborators during the total solar eclipse on May 29. The solar eclipse allowed the stars near the Sun to be observed.
Vertical circle instrument In astronomy, a vertical circle is a great circle on the celestial sphere that is perpendicular to the horizon. Therefore, it contains the vertical direction, passing through the zenith and the nadir. There is a vertical circle for any given azimuth, where azimuth is the angle measured east from the north on the celestial horizon. The vertical circle which is on the east–west direction is called the prime vertical.
The star has a relatively high proper motion, traversing the celestial sphere at the rate of 0.204 arc seconds per annum. This object is an ordinary F-type main-sequence star with a stellar classification of F5V. It is an estimated 2.3 billion years old and is spinning with a projected rotational velocity of 18.8 km/s. The star has 1.4 times the mass of the Sun and 1.3 times the Sun's radius.
Right ascension is the celestial equivalent of terrestrial longitude. Both right ascension and longitude measure an angle from a primary direction (a zero point) on an equator. Right ascension is measured from the Sun at the March equinox i.e. the First Point of Aries, which is the place on the celestial sphere where the Sun crosses the celestial equator from south to north at the March equinox and is currently located in the constellation Pisces.
Representing of Niigata Prefecture, Team SD-R consists of identical triplets whose strategy consists mainly of collecting data from their opponents' previous matches. After being eliminated in the quarterfinals, the triplets help the Try Fighters by sending them their collected data on team Celestial Sphere. ; : :Gunpla:SDG-R1 Snibal Gundam :Leader of Team SD-R. After failing to enter Gunpla Academy, he assembles his team to exact his revenge in the national tournament.
Although the astronomical armillary sphere (representing the celestial sphere) had existed in China since the 1st century BCE, the mathematician and court astronomer Zhang Heng (78–139 CE) provided it with motive power by using the constant pressure head of an inflow water clock to rotate a waterwheel that acted on a set of gears.Needham (1986c), 30 & 479 footnote e; de Crespigny (2007), 1050; Morton & Lewis (2005), 70; Bowman (2000), 595; Temple (1986), 37.
Dales 1980, p. 540. Thomas Aquinas (c.1225–1274), following Avicenna, interpreted Aristotle to mean that there were two immaterial substances responsible for the motion of each celestial sphere, a soul that was an integral part of its sphere, and an intelligence that was separate from its sphere. The soul shares the motion of its sphere and causes the sphere to move through its love and desire for the unmoved separate intelligence.
One of the first catalogs of X-ray sources published came from workers at the US Naval Research Laboratory in 1966 and contained 35 X-ray sources. Of these only 22 had been confirmed by 1968. An additional astronomical catalog of discrete X-ray sources over the celestial sphere by constellation contains 59 sources as of December 1, 1969, that at the least had an X-ray flux published in the literature.
He was also President of the Mathematical Association in 1900. In 1908 he published A Treatise on Spherical Astronomy,R. S. Ball (1908) A Treatise on Spherical Astronomy Google preview which is a textbook on astronomy starting from spherical trigonometry and the celestial sphere, considering atmospheric refraction and aberration of light, and introducing basic use of a generalised instrument. His work The Story of the Heavens is mentioned in the "Ithaca" chapter of Ulysses.
At the time, the resort was expected to include a "celestial sphere" which would display guests' selfie images, a feature that was expected to appeal to millennial customers. By July 2016, Genting was finalizing designs for the hotel tower and the casino floor, ahead of plans to complete foundation work. The hotel tower was expected to begin rising by the end of 2016. In October 2016, approximately 30 people were on the site performing minor construction work.
In mapmaking, a quadrilateralized spherical cube, or quad sphere for short, is an equal-area mapping and binning scheme for data collected on a spherical surface (either that of the Earth or the celestial sphere). It was first proposed in 1975 by Chan and O'Neill for the Naval Environmental Prediction Research Facility. This scheme is also often called the COBE sky cube, because it was designed to hold data from the Cosmic Background Explorer (COBE) project.
In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between −55.68° and −64.70°. Its totality figures at least part of the year south of the 25th parallel north. In tropical regions Crux can be seen in the sky from April to June. Crux is exactly opposite to Cassiopeia on the celestial sphere, and therefore it cannot appear in the sky with the latter at the same time.
17 Cygni is the Flamsteed designation for a binary star system in the northern constellation of Cygnus. It has an apparent visual magnitude of 5.00, so, according to the Bortle scale, it is visible from suburban skies at night. Measurements made with the Hipparcos spacecraft show an annual parallax shift of 0.0478″, which is equivalent to a distance of around from the Sun. It has a relatively high proper motion, traversing the celestial sphere at the rate of /year.
According to Aristotle, the Sun, Moon, planets and starsare embedded in perfectly concentric "crystal spheres" that rotate eternally at fixed rates. Because the celestial spheres are incapable of any change except rotation, the terrestrial sphere of fire must account for the heat, starlight and occasional meteorites.Aristotle, meteorology. The lowest, lunar sphere is the only celestial sphere that actually comes in contact with the sublunary orb's changeable, terrestrial matter, dragging the rarefied fire and air along underneath as it rotates.
72 Cygni is a star in the northern constellation of Cygnus, located 299 light years from the Sun and a member of the Hercules stream. It is visible to the naked eye as a fain, orange-hued star with an apparent visual magnitude of 4.87. 72 Cyg is moving closer to the Earth with a heliocentric radial velocity of −68 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of per year.
Northern Cross, shown in bold green The Northern Cross is an astronomical asterism in the northern hemisphere of the celestial sphere, corresponding closely with the constellation Cygnus The Swan. It is much larger than the Southern Cross and consists of the brightest stars in Cygnus, Deneb, Sadr, Gienah, Delta Cygni and Albireo. The 'head' of the cross, Deneb, is also part of the Summer Triangle asterism. Like the Summer Triangle, the Northern Cross is an indicator of the seasons.
The star is moving further from the Earth with a heliocentric radial velocity of −27 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of per year. The stellar classification of 23 And is F0 IV, matching an F-type subgiant star that is in the process of evolving into a red giant. It displays a slight microvariability with a frequency of 0.85784 d−1 and an amplitude of 0.0062 magnitude.
32 Boötis is a single star in the northern constellation of Boötes, located 360 light years away from the Sun. It is visible to the naked eye as a faint, yellow-hued star with an apparent visual magnitude of 5.55. This object is moving closer to the Earth with a heliocentric radial velocity of −23 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.195 arc seconds per annum.
15 Boötis is a binary star system in the northern constellation of Boötes, located approximately 260 light years away from the Sun. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.45. The system has a relatively high proper motion, traversing the celestial sphere at the rate of 0.166 arc seconds per annum. It is moving away from the Earth with a heliocentric radial velocity of +16.8 km/s.
20 Boötis is a single star in the northern constellation of Boötes, located 183 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.84. The star has a relatively high proper motion, traversing the celestial sphere at the rate of 0.154 arc seconds per annum. It is moving closer to the Earth with a heliocentric radial velocity of −8 km/s.
The foundations of the theoretical structure used in astrology originate with the Babylonians, although widespread usage did not occur till the start of the Hellenistic period after Alexander the Great swept through Greece. It was not known to the Babylonians that the constellations are not on a celestial sphere and are very far apart. The appearance of them being close is illusory. The exact demarcation of what a constellation is, is cultural, and varied between civilisations.
Due to forces that the Sun and Moon exert, Earth's equatorial plane moves with respect to the celestial sphere. Earth rotates while the ECI coordinate system does not. Earth-centered inertial (ECI) coordinate frames have their origins at the center of mass of Earth and do not rotate with respect to the stars. ECI frames are called inertial, in contrast to the Earth-centered, Earth-fixed (ECEF) frames, which remain fixed with respect to Earth's surface in its rotation.
Their influence on lesser beings is purely the result of an "aspiration or desire","Cosmological Argument for the Existence of God", in Macmillan Encyclopedia of Philosophy (1967), Vol. 2, p. 233ff. and each aetheric celestial sphere emulates one of the unmoved movers, as best it can, by uniform circular motion. The first heaven, the outmost sphere of fixed stars, is moved by a desire to emulate the prime mover (first cause),Aristotle, Physics VIII 6, 258 b26-259 a9.
The Earth rotates on its axis, and revolves in an elliptical orbit around the Sun. An excellent approximation assumes that the Sun revolves around a stationary Earth on the celestial sphere, which rotates every 24 hours about its celestial axis. The celestial axis is the line connecting the celestial poles. Since the celestial axis is aligned with the axis about which the Earth rotates, the angle of the axis with the local horizontal is the local geographical latitude.
Newcomb (1906), p. 92-93. As the celestial sphere is considered arbitrary or infinite in radius, all observers see the celestial equator, celestial poles, and ecliptic at the same place against the background stars. From these bases, directions toward objects in the sky can be quantified by constructing celestial coordinate systems. Similar to geographic longitude and latitude, the equatorial coordinate system specifies positions relative to the celestial equator and celestial poles, using right ascension and declination.
Horizontal coordinates use a celestial sphere centered on the observer. Azimuth is measured eastward from the north point (sometimes from the south point) of the horizon; altitude is the angle above the horizon. The horizontal coordinate system, also known as topocentric coordinate system, is a celestial coordinate system that uses the observer's local horizon as the fundamental plane. Coordinates of an object in the sky are expressed in terms of altitude (or elevation) angle and azimuth.
In the huntian () theory of the celestial sphere, the ancient Chinese believed that the earth was flat and square, while the heavens were spherical in shape, along with celestial bodies such as the sun and moon (described by 1st-century AD polymathic scientist and statesman Zhang Heng like a crossbow bullet and ball, respectively).Needham, Joseph; Wang, Ling. (1995) [1959]. Science and Civilization in China: Mathematics and the Sciences of the Heavens and the Earth, vol. 3, reprint edition.
The star has a relatively high proper motion, traversing the celestial sphere at the rate of 0.195 arc seconds per annum. This is an aging giant star with a stellar classification of K4.5 III. It displays an enhanced abundance of elements generated through the alpha process, and, in particular, has a strong enhancement of silicon. 29 Herculis is a suspected variable star of unknown type, and has been measured ranging in visual magnitude from 4.82 down to 4.85.
2 Sextantis is a single star that is now in the equatorial constellation Hydra, located around 295 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.68. This object is moving further from the Earth with a heliocentric radial velocity of +44.6 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of per year.
16 Cephei is a single star located about 119 light years away from the Sun in the constellation of Cepheus. It is visible to the naked eye as a faint, yellow-white hued star with an apparent visual magnitude of 5.036. The star has a relatively high proper motion, traversing the celestial sphere at the rate of 0.174 arc seconds per annum. It is moving closer to the Earth with a heliocentric radial velocity of −21 km/s.
Another track, "The Celestial Sphere", written by Hodges, Smith and Snedden, became Ilium's first music video. Daniel Böhm from German metal magazine, Rock Hard, found the album "sounds wonderfully wrong-headed". After recording the album, Peter Gilchrist joined on bass guitar, while drummer David Walmsley joined shortly thereafter. Snedden left in July due to family and financial restraints, Lord Tim was recruited in his place, originally to complete the recording sessions but soon became a full-time member.
Right ascension (blue) and declination (green) as seen from outside the celestial sphere. The Earth's axis rotates slowly westward about the poles of the ecliptic, completing one circuit in about 26,000 years. This effect, known as precession, causes the coordinates of stationary celestial objects to change continuously, if rather slowly. Therefore, equatorial coordinates (including declination) are inherently relative to the year of their observation, and astronomers specify them with reference to a particular year, known as an epoch.
16 Persei is a single, suspected variable star in the northern constellation of Perseus, located approximately 121 light years away based on parallax. It is visible to the naked eye as a yellow-white hued star with an apparent visual magnitude of 4.22. This object is moving further from the Earth with a heliocentric radial velocity of +14 km/s. It displays a relatively high proper motion, traversing the celestial sphere at the rate of per year.
The selected stars for navigation are often used for sextant observations. Fifty-eight selected navigational stars are given a special status in the field of celestial navigation. Of the approximately 6,000 stars visible to the naked eye under optimal conditions, the selected stars are among the brightest and span 38 constellations of the celestial sphere from the declination of −70° to +89°. Many of the selected stars were named in antiquity by the Babylonians, Greeks, Romans, and Arabs.
All of the selected stars have had a common name since 1953, and many were named in antiquity by the Arabs, Greeks, Romans, and Babylonians. Bayer's naming convention has been in use since 1603, and consists of a Greek letter combined with the possessive form of the star's constellation. Both names are shown for each star in the tables and charts below. Each star's approximate position on the celestial sphere is given using the equatorial coordinate system.
4 Camelopardalis is a binary star in the northern constellation of Camelopardalis, located 179 light years away from the Sun, based upon parallax. With a combined apparent visual magnitude of 5.29, it is visible to the naked eye as a faint, white-hued star. The pair have a relatively high proper motion, traversing the celestial sphere at an angular rate of per year. The system's proper motion makes it a candidate for membership in the IC 2391 supercluster.
11 Cephei is a single star in the northern constellation of Cepheus, located 184 light years away from the Sun. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.55. The star has a relatively high proper motion, traversing the celestial sphere at the rate of 0.153 arc seconds per annum. It is moving closer to the Earth with a heliocentric radial velocity of −38 km/s.
Beta Trianguli Australis, Latinized from β Trianguli Australis, is a double star in the southern circumpolar constellation of Triangulum Australe. It is approximately from Earth and has an apparent visual magnitude of +2.85. This star has a relatively high rate of proper motion across the celestial sphere. It is a F-type main-sequence star with a stellar classification of F1 V. Beta TrA has a 14th magnitude optical companion at an angular separation of 155 arcseconds.
Solrad 10 was a 12-sided cylinder that measured in diameter and in height. Four symmetrically placed solar cell panels, hinged at the central section of the structure, served as the elements of a turnstile antenna system. 18 solar sensors were mounted pointing parallel to the spin axis of the satellite, which pointed directly at the solar disk. The plane of rotation shifted about 1°/day so that a stellar detector mounted to point radially outward from the axis scanned the celestial sphere.
Uttarāyaṇa, the six-month period when the sun travels towards the north on the celestial sphere, starts on Makara Sankranti and ends on Karka Sankranti (around 14 July). One of the places where a large number of devout Hindus reach on 14 January for worship is Sabarimala located in thick rain forests of Kerala. Makara Jyothi is a star which is worshiped by pilgrims in huge numbers at Sabarimala Temple in Kerala on Makara Sankranti on 14 January every year.
Rahu rules the zodiac sign of Aquarius together with Shani. Astronomically, Rahu and Ketu denote the points of intersection of the paths of the Sun and the Moon as they move on the celestial sphere. Therefore, Rahu and Ketu are respectively called the north and the south lunar nodes. The fact that eclipses occur when the Sun and the Moon are at one of these points gives rise to the understanding of swallowing of the Sun and the Moon by the snake.
35 Pegasi is a single star in the northern constellation of Pegasus. It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.80. The star is located approximately 155 light years away from the Sun based on parallax, and is drifting further away with a radial velocity of +54 km/s. The star has a relatively high proper motion, traversing the celestial sphere at the rate of 0.318 arc seconds per annum.
In Kepler's mature celestial physics, the spheres were regarded as the purely geometric spatial regions containing each planetary orbit rather than as the rotating physical orbs of the earlier Aristotelian celestial physics. The eccentricity of each planet's orbit thereby defined the radii of the inner and outer limits of its celestial sphere and thus its thickness. In Kepler's celestial mechanics, the cause of planetary motion became the rotating Sun, itself rotated by its own motive soul.Johannes Kepler, Epitome of Copernican Astronomy, vol.
14 Boötis is a possible binary star system located 110 light years away from the Sun in the northern constellation of Boötes. It is visible to the naked eye as a dim, yellow-white hued star with a combined apparent visual magnitude of 5.53. This system is moving closer to the Earth with a heliocentric radial velocity of −40 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.260 arc seconds per annum.
The apparent motion of the Sun along the ecliptic (red) as seen on the inside of the celestial sphere. Ecliptic coordinates appear in (red). The celestial equator (blue) and the equatorial coordinates (blue), being inclined to the ecliptic, appear to wobble as the Sun advances. The celestial equator and the ecliptic are slowly moving due to perturbing forces on the Earth, therefore the orientation of the primary direction, their intersection at the Northern Hemisphere vernal equinox, is not quite fixed.
At such conjunction both objects have the same ecliptic longitude. Conjunction in right ascension and conjunction in ecliptic longitude do not normally take place at the same time, but in most cases nearly at the same time. However, at triple conjunctions, it is possible that a conjunction only in right ascension (or ecliptic length) occurs. At the time of conjunction – it does not matter if in right ascension or in ecliptic longitude – the involved planets are close together upon the celestial sphere.
Constellation families are collections of constellations sharing some defining characteristic, such as proximity on the celestial sphere, common historical origin, or common mythological theme. In the Western tradition, most of the northern constellations stem from Ptolemy's list in the Almagest (which in turn has roots that go back to Mesopotamian astronomy), and most of the far southern constellations were introduced by sailors and astronomers who traveled to the south in the 16th to 18th centuries. Separate traditions arose in India and China.
Known titles of his works include two books on the celestial sphere, one on the Greek system and the other on "barbarian", or non-Greek, systems, a surviving fragment of which indicates that he treated Egyptian astrology.A. Swoboda, P. Nigidii Figuli Operum Reliquiae (Amsterdam 1964), p.128. His astrological work drew on the Etruscan tradition and influenced Martianus Capella, though probably through an intermediary source.Stefan Weinstock, "Martianus Capella and the Cosmic System of the Etruscans," Journal of Roman Studies 36 (1946) 101–129.
It is a mid-sized constellation, ranking 39th overall size, with an area of 441 square degrees (1.1% of the celestial sphere). Although Aries came to represent specifically the ram whose fleece became the Golden Fleece of Ancient Greek mythology, it has represented a ram since late Babylonian times. Before that, the stars of Aries formed a farmhand. Different cultures have incorporated the stars of Aries into different constellations including twin inspectors in China and a porpoise in the Marshall Islands.
Meridians, celestial and terrestrial, are determined by the axial-pencil of planes passing through the axis of Earth's rotation. For a location not at a geographical pole there is a unique plane in this axial-pencil through that location. The intersection of this plane with Earth's surface is the geographical meridian, and the intersection of the plane with the celestial sphere is the celestial meridian for that location and time. There are several ways to divide the meridian into semicircles.
Hypothetical observation of γ Draconis if its movement was caused by parallax. Hypothetical observation of γ Draconis and 35 Camelopardalis if their movements were caused by nutation. Bradley and Molyneux discussed several hypotheses in the hope of finding the solution. Since the apparent motion was evidently caused neither by parallax nor observational errors, Bradley first hypothesized that it could be due to oscillations in the orientation of the Earth's axis relative to the celestial sphere – a phenomenon known as nutation.
Based on Campion's summary, most published materials on the subject state that the Age of Aquarius arrived in the 20th century (29 claims), with the 24th century in second place with twelve claimants. Astrological ages are taken to be associated with the precession of the equinoxes. The slow wobble of the earth's rotation axis on the celestial sphere is independent of the diurnal rotation of the Earth on its own axis and the annual revolution of the earth around the sun.
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.
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.
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.
B. L. van der Waerden, "History of the zodiac", Archiv für Orientforschung 16 (1953) 216–230. The term "zodiac" may also refer to the region of the celestial sphere encompassing the paths of the planets corresponding to the band of about 8 arc degrees above and below the ecliptic. The zodiac of a given planet is the band that contains the path of that particular body; e.g., the "zodiac of the Moon" is the band of 5° above and below the ecliptic.
In terms of cosmology, according to Davidson (p. 82) "Avicenna's universe has a structure virtually identical with the structure of Alfarabi's" but there are differences in details. As in Al Farabi, there are several levels of intellect, intelligence or nous, each of the higher ones being associated with a celestial sphere. Avicenna however details three different types of effect which each of these higher intellects has, each "thinks" both the necessary existence and the possible being of the intelligence one level higher.
Consequently, the period of their power became one of many scholarly achievements. The rein of Sultan Ulugh Begh saw the scientific peak of the empire. During his rule, al- Kashi produced sine tables to four sexagesimal digits (equivalent to eight decimal places) of accuracy for each degree and includes differences for each minute. He also produced tables dealing with transformations between coordinate systems on the celestial sphere, such as the transformation from the ecliptic coordinate system to the equatorial coordinate system.
Boötes is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from the Greek Βοώτης, Boōtēs, meaning “herdsman” or “plowman” (literally, “ox-driver”; from βοῦς bous “cow”). One of the 48 constellations described by the 2nd-century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the fourth-brightest star in the night sky, the orange giant Arcturus.
Gall's main work as an astronomer was with the constellations. As part of this work he developed the Gall orthographic projection, a derivative of the Lambert cylindrical equal-area projection, to project the celestial sphere onto flat paper in a manner that avoided distorting the shapes of the constellations. He also applied this technique to terrestrial mapmaking as a way to make a flat map of the round Earth. Gall Orthographic was re-invented by Arno Peters in 1967 and adopted by organisations such as UNESCO.
The constellation Indus (the Indian) first appeared in Johann Bayer's celestial atlas Uranometria in 1603. The 1801 star atlas Uranographia, by German astronomer Johann Elert Bode, places ε Indi as one of the arrows being held in the left hand of the Indian. In 1847, Heinrich Louis d'Arrest compared the position of this star in several catalogues dating back to 1750, and discovered that it possessed a measureable proper motion. That is, he found that the star had changed position across the celestial sphere over time.
88 Leonis is a wide binary star system in the equatorial constellation of Leo, the lion. The system is near the lower limit of visibility to the naked eye with an apparent visual magnitude of 6.27. It is located at a distance of 77 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −4.8 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.379 arc seconds per annum.
The north–south component of the analemma shows the Sun's declination, its latitude on the celestial sphere, or the latitude on the Earth at which the Sun is directly overhead. The east–west component shows the equation of time, or the difference between solar time and local mean time. This can be interpreted as how "fast" or "slow" the Sun (or a sundial) is compared to clock time. It also shows how far west or east the Sun is, compared with its mean position.
38 Aurigae is a star located 236 light years away from the Sun in the northern constellation of Auriga. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 6.08. The star is moving further from the Earth with a heliocentric radial velocity of +34 km/s, and it has a relatively high proper motion, traversing the celestial sphere at the rate of 0.181 arc seconds per annum. It is a probable member of the Hercules stream.
5 Andromedae is moving closer to the Sun with a radial velocity of −2.6 km/s. It has a relatively high proper motion, advancing across the celestial sphere at the rate of 0.201 arc seconds per year. This is an ordinary F-type main-sequence star with a stellar classification of F5 V. It is estimated to be 2.3 billion years old and is spinning with a projected rotational velocity of 9.7 km/s. The star has 1.39 times the mass of the Sun.
HD 219623 is the Henry Draper Catalogue designation for a solitary star in the northern circumpolar constellation of Cassiopeia. It has an apparent visual magnitude of 5.59, which lies in the brightness range that is visible to the naked eye. According to the Bortle scale, it can be observed from dark suburban skies. Parallax measurements made by the Hipparcos spacecraft place it at an estimated distance of around 66.9 light years. It has a relatively high proper motion, advancing 262 milliarcseconds per year across the celestial sphere.
Some examples of great circles on the celestial sphere include the celestial horizon, the celestial equator, and the ecliptic. Great circles are also used as rather accurate approximations of geodesics on the Earth's surface for air or sea navigation (although it is not a perfect sphere), as well as on spheroidal celestial bodies. The equator of the idealized earth is a great circle and any meridian and its opposite meridian form a great circle. Another great circle is the one that divides the land and water hemispheres.
The angle may be expressed as negative east of the meridian plane and positive west of the meridian plane, or as positive westward from 0° to 360°. The angle may be measured in degrees or in time, with 24h = 360° exactly. In astronomy, hour angle is defined as the angular distance on the celestial sphere measured westward along the celestial equator from the meridian to the hour circle passing through a point. It may be given in degrees, time, or rotations depending on the application.
HD 3167 is a single, orange-hued star in the zodiac constellation of Pisces that hosts a system with three exoplanets. The star is too faint to be seen with the naked eye, having an apparent visual magnitude of 8.97. The distance to HD 3167 can be determined from its annual parallax shift of as measured by the Gaia space observatory, yielding a range of 154 light years. It has a relatively high proper motion, traversing the celestial sphere at the rate of per year.
23, p. 21-24 Spectrographic Observations of Nebulae, in which he states, "The early discovery that the great Andromeda spiral had the quite exceptional velocity of - 300 km(/s) showed the means then available, capable of investigating not only the spectra of the spirals but their velocities as well." Slipher reported the velocities for 15 spiral nebula spread across the entire celestial sphere, all but three having observable "positive" (that is recessional) velocities. In 1914, Slipher also made the first discovery of the rotation of spiral galaxies.
During the day, the sky is seen as a deep blue due to the sunlight reflected on the air. Astronomically speaking, the sky is a celestial sphere–an imaginary dome divided into constellations–where the moon, planets, stars and sun seem to visually move across the sky. Although artists have long painted the sky it was Edward Hopper who first showed us the beauty of the skyscape, sans clouds. In the 1950s, Eric Sloane painted many cloudless skyscapes during his stay in Taos, New Mexico.
For example, on a compact Riemann surface there are no non-constant holomorphic maps to the complex numbers, but holomorphic maps to the complex projective line are abundant. The Riemann sphere has many uses in physics. In quantum mechanics, points on the complex projective line are natural values for photon polarization states, spin states of massive particles of spin , and 2-state particles in general (see also Quantum bit and Bloch sphere). The Riemann sphere has been suggested as a relativistic model for the celestial sphere.
Caravaggio has painted an allegory of the alchemical triad of Paracelsus: Jupiter stands for sulphur and air, Neptune for mercury and water, and Pluto for salt and earth. Each figure is identified by his beast: Jupiter by the eagle, Neptune by the hippocamp, and Pluto by the three- headed dog Cerberus. Jupiter is reaching out to move the celestial sphere in which the Sun revolves around the Earth. Galileo was a friend of Del Monte but had yet to make his mark on cosmology.
The star has a relatively high proper motion, traversing the celestial sphere at the rate of 0.353 arc seconds per year. It is moving closer to the Sun with a radial velocity of −35.6 km/s. This is an ordinary F-type main-sequence star with a stellar classification of F5 V. It has 1.23 times the mass of the Sun and 1.64 times the Sun's radius. The star is around three billion years old and is spinning with a projected rotational velocity of 8 km/s.
83 Cancri has a relatively high proper motion, traversing the celestial sphere at an angular rate of per annum. The pair have an orbital period of around 32 days and an eccentricity of about 0.6. The visible member of this system, designated component A, is an F-type main- sequence star with a stellar classification of F4V. Its atmosphere is enhanced with s-process elements, particularly strontium and yttrium, which is attributed to mass transfer from the companion while the latter was on the asymptotic giant branch.
53 Virginis is a single, yellow-white hued star in the zodiac constellation of Virgo. It is faintly visible to the naked eye, having an apparent visual magnitude of 5.04. Based upon an annual parallax shift of , it is located 111 light years away. The star is moving closer to the Sun with a heliocentric radial velocity of −12.7 km/s. It has a relatively high rate of proper motion, traversing the celestial sphere at the rate of along a position angle of 162.2°.
38 Leonis Minoris is a binary star system in the northern constellation of Leo Minor. It shines with a combined light of apparent magnitude 5.84, which indicates it a dimly visible to the naked eye under good viewing conditions. An annual parallax shift of 19.11 mas provides a distance estimate of around 171 light years. It has a relatively high proper motion, traversing the celestial sphere at a rate of 0.226 arcseconds per year, and is moving away from the Sun with a radial velocity of +31 km/s.
Sigma Draconis has a high proper motion, advancing across the celestial sphere at a rate of 1.835 arc seconds per year. The star made its perihelion passage about 46,725 years ago, when it came within . The components of Sigma Draconis's space velocity are U=+36, V=+40 and W=-10 km/s. This gives the star an unusually large orbital eccentricity about the Milky Way galaxy of 0.30 (compared to 0.06 for the Sun.) The mean galactocentric distance for the orbit is 10.3 kiloparsecs (about 34,000 light-years).
The galactic anticenter is located about 3.5° to the east of Beta Aurigae. This marks the point on the celestial sphere opposite the location of the Galactic Center; hence, this region marks a less extensive and less luminous part of the dust band that forms the spiral arms of the Milky Way. Auriga has many open clusters and other objects because the Milky Way runs through it. The three brightest open clusters are M36, M37 and M38, all of which are visible in binoculars or a small telescope in suburban skies.
It is moving closer to the Earth with a heliocentric radial velocity of −33 km/s, and has a relatively high proper motion, traversing the celestial sphere at the rate of per year. 27 Cygni is a G-type subgiant with a stellar classification of G8.5 IVa, a star that has used up its core hydrogen and is starting to expand. It was found to be slightly variable by Percy et al. (1986), changing by up to 0.05 in visual magnitude with a characteristic time scale of 50–60 days.
The ultimate limit of the universe was the primum mobile, whose diurnal rotation was conferred upon it by a transcendental God, not part of the universe (although, as the kingdom of heaven, adjacent to itSee e.g. Cosmography by Peter Apian, Antwerp 1539 and its outer sphere), a motionless prime mover and first cause. The fixed stars were part of this celestial sphere, all at the same fixed distance from the immobile Earth at the center of the sphere. Ptolemy had numbered these at 1,022, grouped into 48 constellations.
Horologium (Latin , the pendulum clock, from Greek , ) is a constellation of six stars faintly visible in the southern celestial hemisphere. It was first described by the French astronomer Nicolas-Louis de Lacaille in 1756 and visualized by him as a clock with a pendulum and a second hand. In 1922 the constellation was redefined by the International Astronomical Union (IAU) as a region of the celestial sphere containing Lacaille's stars, and has since been an IAU designated constellation. Horologium's associated region is wholly visible to observers south of 23°N.
In 1815, when Brazil gained the status of kingdom united with that of Portugal, its coat of arms was formalized as a golden armillary sphere in a blue field. Representing Brazil, the armillary sphere became also present in the arms and the flag of the United Kingdom of Portugal, Brazil and the Algarves. When Brazil became independent as an empire in 1822, the armillary sphere continued to be present in its national arms and in its national flag. The celestial sphere of the present Flag of Brazil replaced the armillary sphere in 1889.
The detection size threshold is about 2 cm at 1000 km range. The radar conducts regular ‘beam park’ experiments, where the radar beam is pointed in a fixed direction on the celestial sphere for 24 hours, scanning 360° in a narrow strip a complete Earth rotation. The tracking sensitive can be enhanced when the TIRA system is used as a transmitter, part of a bistatic radar system. In conjunction with the Effelsberg Radio Telescope, functioning as a receiver, the combined system has a detection size threshold of 1 cm.
Finally, the natural place of fire is higher than that of air but below the innermost celestial sphere (carrying the Moon). In Book Delta of his Physics (IV.5), Aristotle defines topos (place) in terms of two bodies, one of which contains the other: a "place" is where the inner surface of the former (the containing body) touches the outer surface of the other (the contained body). This definition remained dominant until the beginning of the 17th century, even though it had been questioned and debated by philosophers since antiquity.
Located southwest of Orion in the southern-hemisphere constellation Fornax, the rectangular image is 2.4 arcminutes to an edge, or 3.4 arcminutes diagonally. This is approximately one tenth of the angular diameter of a full moon viewed from Earth (which is less than 34 arcminutes), smaller than 1 sq. mm piece of paper held at 1 meter away, and equal to roughly one twenty-six-millionth of the total area of the sky. The image is oriented so that the upper left corner points toward north (−46.4°) on the celestial sphere.
Dakshinayana () is the six-month period between Summer solstice and Winter solstice, when the sun travels towards the south on the celestial sphere. Dakshinayana begins on Karkada Sankranti or July 16, as it marks the transition of the Sun into Karkada rashi (Cancer). It marks the end of the six-month Uttarayana period of Hindu calendar and the beginning of Dakshinayana, which itself ends at Makar Sankranti and the Uttarayan period begins. According to the Puranas, Dakshinayana marks the period when the Gods and Goddesses are in their celestial sleep.
41 Andromedae is a single star in the northern constellation of Andromeda. 41 Andromedae is the Flamsteed designation. It is bright enough to be faintly visible to the naked eye, having an apparent visual magnitude of 5.04. Based upon an annual parallax shift of , it is located 178 light years away. The star is moving further from the Earth with a heliocentric radial velocity of +10 km/s and it has a relatively high rate of proper motion, traversing the celestial sphere at the rate of per year.
Traditional Western astrology is based on tropical astrology, which presumes an equal division of the celestial sphere along the ecliptic into twelve equal parts, starting with Aries. Sidereal astrology, at once the oldest and a recently revived astrological tradition, is more observationally oriented and uses the actual observed position of the stars and the traditional divisions of the zodiac constellations as its starting point. As a result of the precession of the equinoxes, the observed positions of the zodiac signs no longer correspond to the signs of tropical astrology.
The base of the instrument represents the horizon and is built on a hinge and a part known as the stylus holds the instrument up to the viewer's complementary latitude. This represents the celestial equator and the angle varies depending on where the view is located on Earth. The several plates and circles that make up the upper portion of the instrument represent the celestial sphere. These parts are built on top of the base and above the basilica, which rotates on a pin to represent the axis of the Earth.
In astronomy, a celestial coordinate system (or celestial reference system) is a system for specifying positions of satellites, planets, stars, galaxies, and other celestial objects relative to physical reference points available to a situated observer (e.g. the true horizon and north cardinal direction to an observer situated on the Earth's surface). Coordinate systems can specify an object's position in three-dimensional space or plot merely its direction on a celestial sphere, if the object's distance is unknown or trivial. The coordinate systems are implemented in either spherical or rectangular coordinates.
The equatorial coordinate system on the celestial sphere Star position is the apparent location of any given star in the sky, which seems fixed onto an arbitrary sphere centered on Earth. The location is defined by a pair of angular coordinates relative to the celestial equator: right ascension (α) and declination (δ). This pair based the equatorial coordinate system. While δ is given in degrees (from +90° at the north celestial pole to −90° at the south), α is usually given in hour angles (0 to 24 h).
In some cases, sunbeams may extend across the sky and appear to converge at the antisolar point, the point on the celestial sphere opposite of the Sun's direction. In this case, they are called antisolar rays (anytime not during astronomical night) or anticrepuscular rays (during the twilight period). This apparent dual convergence (at both the solar and the antisolar points) is a perspective effect analogous to the apparent dual convergence of the parallel lines of a long straight road or hallway at directly opposite points (to an observer above the ground).
The sky was divided into constellations by historic astronomers, according to perceived patterns in the sky. At first, only the shapes of the patterns were defined, and the names and numbers of constellations varied from one star map to another. Despite being scientifically meaningless, they do provide useful reference points in the sky for human beings, including astronomers. In 1930, the boundaries of these constellations were fixed by Eugène Joseph Delporte and adopted by the IAU, so that now every point on the celestial sphere belongs to a particular constellation.
HD 2454 is a probable binary star system in the zodiac constellation of Pisces. With an apparent visual magnitude of 6.04, it is near the lower limit of visibility to the naked eye under good seeing conditions. An annual parallax shift of 27.36 mas as measured from Earth's orbit provides a distance estimate of 199 light years. It has a relatively high proper motion, traversing the celestial sphere at a rate of 0.208 arcseconds per year, and is moving closer to the Sun with a heliocentric radial velocity of −10 km/s.
While Jannah in the Quran is often translated as "Heaven" in the sense of an abode where believers are rewarded in afterlife, samāʾ (usually pl. samāwāt) is the word for heaven in the sense of firmament or celestial sphere, as "seven heavens" (2:29, 78:12). Some sources connect the two in some way. According to Sufi cosmology, Paradise is often depicted as being above the seven heavensSachiko Murata The Tao of Islam: A Sourcebook on Gender Relationships in Islamic Thought SUNY Press 1992 page 127 or between the sixth and seventh heaven.
17 Crateris is a wide binary star system in the equatorial constellation of Hydra, located 90.5 light years away from the Sun. It is visible to the naked eye as a faint, yellow-white hued star with a combined apparent visual magnitude of 4.93. The system is traversing the celestial sphere with a relative proper motion of /y, and is moving away from the Earth with a heliocentric radial velocity of +5.8 km/s. The dual nature of this system was discovered by W. Herschel in 1783, when they showed an angular separation of .
Usually, the scales are chosen so that equal distances on the diagram represent equal angles in both directions on the celestial sphere. Thus 4 minutes (more precisely 3 minutes, 56 seconds), in the equation of time, are represented by the same distance as 1° in the declination, since Earth rotates at a mean speed of 1° every 4 minutes, relative to the Sun. An analemma is drawn as it would be seen in the sky by an observer looking upward. If north is shown at the top, then west is to the right.
The meridian on the celestial sphere. An observer's upper meridian, a semicircle, passes through their zenith and the north and south points of their horizon (see yellow hemi-disk); the observer's local meridian is the semicircle that contains their zenith and both celestial poles. In astronomy, the meridian is the great circle passing through the celestial poles, as well as the zenith and nadir of an observer's location. Consequently, it contains also the north and south points on the horizon, and it is perpendicular to the celestial equator and horizon.
Anaximander proposed a differing perspective from other later astronomers in proposing the fixed stars were nearest of the heavenly bodies to the earth. Other models of the planetary system show a celestial sphere containing fixed stars on the outer most part of the universe. Aristotle and other like Greek thinkers of antiquity, and later the Ptolemaic model of the cosmos demonstrated an Earth-centered universe. This geocentric view was held through the Middle Ages and was later countered by subsequent astronomers and mathematicians alike, such as Nicolaus Copernicus and Johannes Kepler.
The Winter Hexagon and the Winter Triangle (dashed) with all involved constellations and the Moon incidentally within. All stars of an apparent magnitude of at least 2 mag are labelled. Winter constellations as seen from the tropics Flip book (158 images): Transit of Mars, Sun, Mercury, and Venus in 2017 The Winter Hexagon or Winter Circle/Oval is an asterism appearing to be in the form of a hexagon with vertices at Rigel, Aldebaran, Capella, Pollux, Procyon, and Sirius. It is mostly upon the Northern Hemisphere's celestial sphere.
The outer envelope of this star is radiating energy at an effective temperature of 4,545 K, resulting an orange hue that is typical of a cool, K-type star. Beta Columbae has a high proper motion across the celestial sphere and is moving at an unusually large speed of relative to the Sun. About 107,200 years ago, it made a close approach to the Beta Pictoris system. The estimated separation of the two stars at this time was around and Beta Columbae may have perturbed outlying planetesimals within the debris disk surrounding Beta Pictoris.
Valdis Muktupāvels regards kokles as the most highly socially and economically valued Latvian instrument. Mythologically kokles may have been linked with the solar and celestial sphere as they are also sometimes called "Kokles of Dievs" (Dieva kokles) or "golden kokles" (zelta kokles) and sun ornaments were traditionally carved in the soundboard. Kokles, kokles playing (koklēšana) and kokles players (koklētāji) are mentioned in 274 Latvian dainas and mythological kokles players include Jānis and other unnamed sons of Dievs, as well as Saule playing kokles while sitting in the Austras koks.
The show was set in Beverly Hills, California. The four central characters of the show were teens selected by a blobby alien named Nimbar to fight off the monsters sent by the evil Emperor Gorganus. Gorganus is intent on conquering Earth because it is the focal point for a network of "Power Portals" that would facilitate conquest of the galaxy. In the first episode, Nimbar recruits the four high school students and with a touch by his slimy "finger" gives them each a special tattoo based on a constellation in the celestial sphere.
HD 128429 is a binary star system located at a distance of 88 light years from the Sun in the southern zodiac constellation of Libra. It has a yellow-white hue and is just barely visible to the naked eye with an apparent visual magnitude of 6.20. The system is drifting closer to the Sun with a radial velocity of −66 km/s and has a high proper motion, traversing the celestial sphere at the rate of per year. It is a high velocity star system with a net heliocentric velocity of 158.8 km/s.
HR 244 is a single star in the constellation Cassiopeia. It has a yellow-white hue and is visible to the naked eye with an apparent visual magnitude of 4.80. Based upon parallax measurements, it is located at a distance of 61 light years from the Sun, and is drifting further away with a radial velocity of +20.7 km/s; around 546,000 years ago it passed within of the Sun. The star has a relatively high proper motion, traversing the celestial sphere at the rate of per annum.
Evidently from works such as the Apocryphon of John, the Ophite Diagrams, On the Origin of the World and Pistis Sophia, archons play an important role in Gnostic cosmology. Probably originally referring to the Greek daimons of the planets, in Gnosticism they became the demonic rulers of the material world, each associated with a different celestial sphere. As rulers over the material world, they are called ἄρχοντες (, "principalities", or "rulers"). As with ancient astronomy, which thought of a sphere of fixed stars, above the spheres of the seven planets,Clem. Alex.
The structure was commonly referred to as the manor house. Luxuriously furnished, it was in the center of a ring of eucalyptus trees and little gardens and a lily pond, but Harris maintained that his "real palace" was in "interspace." According to Brotherhood guidelines, all of the structures in the Fountain Grove commune were built to be taken physically into the "Celestial Sphere.""Scholars have estimated that Harris believers numbered about 1,000 at the peak of his charismatic career," Fountaingrove History Folder, Gaye LeBaron Collection, Special Collections, University Library, Sonoma State University.
Excerpt translated by D.R. Siefkin. Emmanuel Frémiet's horses The first studies Carpeaux made were of four standing female figures representing the four points of the compass holding a celestial sphere over their heads, but Carpeaux was dissatisfied with the immobility of the figures. In his next models he transformed the women into representatives of the four parts of the world, Europe, Asia, Africa and America, twisting their bodies to turn the sphere, giving the sculpture motion.Catalogue des peintures et sculptures de Jean- Baptiste Carpeaux à Valenciennes, Valenciennes, 1978 (pg. 80-82.).
The system has a relatively high proper motion, traversing the celestial sphere at the rate of per year along a position angle of 14.51°. The visible component is an evolved K-type giant star, based upon a stellar classification of K2 III assigned by Gray et al. (2006). In contrast, Keenan and McNeil (1989) gave it a somewhat less evolved classification of K2 III–IV. It is about eight billion years old with 12% more mass than the Sun, and has expanded to 4.8 times the Sun's radius.
This circle across the celestial sphere forms the apparent path of the Sun as the Earth completes its annual orbit. As the orbital plane of the Moon and the planets lie near the ecliptic, they can usually be found in the constellation Taurus during some part of each year. The galactic plane of the Milky Way intersects the northeast corner of the constellation and the galactic anticenter is located near the border between Taurus and Auriga. Taurus is the only constellation crossed by all three of the galactic equator, celestial equator, and ecliptic.
The star has a relatively high proper motion, traversing the celestial sphere at the rate of /yr. Based upon a stellar classification of F0 IV, this is an aging F-type subgiant star that has consumed the hydrogen at its core. It is spinning rapidly with a projected rotational velocity of 165 km/s, giving it an oblate shape with an equatorial bulge that is estimated to be 8% larger than the polar radius. CL Dra is a Delta Scuti variable, changing brightness with an amplitude of 0.010 magnitude over a period of .
While this star lies in the field of view of the open cluster named Collinder 121, it is unlikely to be a member. In fact, its optical neighbor, the orange supergiant ο1 Canis Majoris has a much higher likelihood of 23.1% based upon its proper motion being a closer match to the motion of the cluster. Although they are located near each other on the celestial sphere, ο1 CMa and ο2 CMa are most likely not gravitationally bound to each other as they appear to lie many light years apart.
25 Cancri is a common proper motion star system in the zodiac constellation of Cancer, located around 348 light years away from the Sun. It has the Bayer designation d2 Cancri (d2 Cnc); 25 Cancri (25 Cnc) is the Flamsteed designation. It is near the lower limit of visibility to the naked eye in good viewing conditions, appearing as a dim, yellow-white hued star with a combined apparent visual magnitude of 6.11. The pair have a relatively high proper motion, traversing the celestial sphere at an angular rate of per year.
The orientation of the BCRS coordinate system coincides with that of the International Celestial Reference System (ICRS). Both are centered at the barycenter of the Solar System, and both "point" in the same direction. That is, their axes are aligned with that of the International Celestial Reference Frame (ICRF), which was adopted as a standard by the IAU two years earlier (1998). The motivation of the ICRF is to define what "direction" means in space, by fixing its orientation in relation to the Celestial sphere, that is, to deep-space background.
70 Virginis is a single star located 58 light years from the Sun in the equatorial constellation of Virgo, near the northern constellation border with Coma Berenices. 70 Virginis is its Flamsteed designation. The star is visible to the naked eye as a faint, yellow-hued point of light with an apparent visual magnitude of +4.97. It is drifting further away with a heliocentric radial velocity of +4.4 km/s and has a high proper motion, traversing the celestial sphere at the rate of 0.621 arc seconds per annum.
The waterwheel was also used for operating trip hammers in pounding grain and in rotating the metal rings of the mechanical-driven astronomical armillary sphere representing the celestial sphere around the Earth. The quality of life was improved with many Han inventions. The Han Chinese had hempen-bound bamboo scrolls to write on, yet by the 2nd century CE had invented the papermaking process which created a writing medium that was both cheap and easy to produce. The invention of the wheelbarrow aided in the hauling of heavy loads.
HR 6594 is the Bright Star Catalogue designation for a binary star system in the northern constellation of Hercules. It is faintly visible to the naked eye with an apparent visual magnitude of 5.55; according to the Bortle scale, it is sufficiently bright to be visible from dark suburban skies. The distance to this system, as determined using parallax measurements, is about 114 light years. On the celestial sphere it is located near the star Alpha Ophiuchi; their projected separation is just 3 light years, although their actual separation is much greater.
A star chart of the entire Northern Sky, centered on the north celestial pole The northern celestial hemisphere, also called the Northern Sky, is the northern half of the celestial sphere; that is, it lies north of the celestial equator. This arbitrary sphere appears to rotate westward around a polar axis due to Earth's rotation. At any given time, the entire Northern Sky is visible from the geographic North Pole, while less of this hemisphere is visible the further south the observer is located. The southern counterpart is the southern celestial hemisphere.
Paul Howard Manship (December 24, 1885 - January 28, 1966) was an American sculptor. He consistently created mythological pieces in a classical style, and was a major force in the Art Deco movement. He is well known for his large public commissions, including the iconic Prometheus in Rockefeller Center and the Celestial Sphere Woodrow Wilson Memorial in Geneva, Switzerland. He is also credited for designing the modern rendition of New York City's official seal Manship gained notice early in his career for rejecting the Beaux-Arts architecture movement and preferring linear compositions with a flowing simplicity.
The central skeletal character in In Ictu Oculi is a personification of death. He holds a coffin under his arm and a scythe in his hand as one foot treads upon a celestial sphere. He stands before various symbols of wealth, power and learning, including scrolls and letters, the globe, jewelry, a tiara (imperial crown), velvet purple and white royal, clerical robes, and some arms. Death extinguishes a candle - the representation of the briefness of life which both lasts and can be ended "In the blink of an eye".
The polarization at twilight at an equinox is represented by the figure to the right. The red band represents the circle in the North-Zenith-South plane where the sky is highly polarized. The cardinal directions N, E, S, W are shown at 12-o'clock, 9 o'clock, 6 o'clock and 3 o'clock (counter-clockwise around the celestial sphere since the observer is looking up at the sky). Note that because the polarization pattern is dependent on the sun, it changes not only throughout the day but throughout the year.
The Spring Triangle with Arcturus, Spica, and Regulus plus (May 2017) Jupiter and, "incidentally", the Moon. The line between Spica and Regulus nearly represents the ecliptic, the path of the sun and planets. Arcturus and Spica are found along an arcing path off the handle of the big dipper, while Regulus can also be found from the big dipper by pointing from down from the third and fourth dipper stars. The Spring Triangle is an astronomical asterism involving an imaginary triangle drawn upon the celestial sphere, with its defining vertices at Arcturus, Spica, and Regulus.
A star chart of the entire Southern Sky, centered on the south celestial pole The southern celestial hemisphere, also called the Southern Sky, is the southern half of the celestial sphere; that is, it lies south of the celestial equator. This arbitrary sphere, on which seemingly fixed stars form constellations, appears to rotate westward around a polar axis due to Earth's rotation. At any given time, the entire Southern Sky is visible from the geographic South Pole, while less of this hemisphere is visible the further north the observer is located. The northern counterpart is the northern celestial hemisphere.
Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle attitude requires sensors to measure vehicle orientation, actuators to apply the torques needed to orient the vehicle to a desired attitude, and algorithms to command the actuators based on (1) sensor measurements of the current attitude and (2) specification of a desired attitude. The integrated field that studies the combination of sensors, actuators and algorithms is called guidance, navigation and control (GNC).
Originally targeting the observation of around 400,000 stars, the resulting Tycho Catalogue comprised just over 1 million stars, with a subsequent analysis extending this to the Tycho-2 Catalogue of about 2.5 million stars. The attitude of the spacecraft about its center of gravity was controlled to scan the celestial sphere in a regular precessional motion maintaining a constant inclination between the spin axis and the direction to the Sun. The spacecraft spun around its Z-axis at the rate of 11.25 revolutions/day (168.75 arc-sec/s) at an angle of 43° to the Sun.
MS Robert Parker manually points ASTRO-1's instruments using a toggle on the aft flight deck. Passing over Lake Eyre, Australia. The primary payload of mission STS-35 was ASTRO-1, the fifth flight of the Spacelab system and the second with the Igloo and pallet train configuration. The primary objectives were round-the-clock observations of the celestial sphere in ultraviolet and X-ray spectral wavelengths with the ASTRO-1 observatory, consisting of four telescopes: Hopkins Ultraviolet Telescope (HUT); Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE); Ultraviolet Imaging Telescope (UIT), mounted on the Instrument Pointing System (IPS).
In Timaeus, Plato posited a "demiurge" of supreme wisdom and intelligence as the creator of the Cosmos. Aristotle argued against the idea of a first cause, often confused with the idea of a "prime mover" or "unmoved mover" ( or primus motor) in his Physics and Metaphysics.Aristotle, Physics VIII, 4–6; Metaphysics XII, 1–6. Aristotle argued in favor of the idea of several unmoved movers, one powering each celestial sphere, which he believed lived beyond the sphere of the fixed stars, and explained why motion in the universe (which he believed was eternal) had continued for an infinite period of time.
And it is this intellectual activity that underlies its role in the creation of the universe. The First Cause, by thinking of itself, "overflows" and the incorporeal entity of the second intellect "emanates" from it. Like its predecessor, the second intellect also thinks about itself, and thereby brings its celestial sphere (in this case, the sphere of fixed stars) into being, but in addition to this it must also contemplate upon the First Cause, and this causes the "emanation" of the next intellect. The cascade of emanation continues until it reaches the tenth intellect, beneath which is the material world.
This was the same discovery made earlier by the ancient Greek astronomer Hipparchus (c. 190-120 BC), who found that the measurements for either the sun's path around the ecliptic to the vernal equinox or the sun's relative position to the stars were not equal in length. Yu Xi wrote a critical analysis of the huntian (渾天) theory of the celestial sphere, arguing that the heavens surrounding the earth were infinite and motionless. He advanced the idea that the shape of the earth was either square or round, but that it had to correspond to the shape of the heavens enveloping it.
Eves, Chapter 2. The ancient Babylonians had known of theorems concerning the ratios of the sides of similar triangles for many centuries, but they lacked the concept of an angle measure and consequently, studied the sides of triangles instead. The Babylonian astronomers kept detailed records of the rising and setting of stars, the motion of the planets, and the solar and lunar eclipses, all of which required familiarity with angular distances measured on the celestial sphere. They also used a form of Fourier analysis to compute ephemeris (tables of astronomical positions), which was discovered in the 1950s by Otto Neugebauer.
It is moving closer to the Earth with a heliocentric radial velocity of −35 km/s, and has a relatively large proper motion, traversing the celestial sphere at a rate of ·yr−1. This is an evolved giant star with a stellar classification of K0 IIIb, where the 'b' suffix indicated a lower luminosity giant. It is a red clump star, which means it is generating energy through helium fusion at its core. This star has an estimated 1.7 times the mass of the Sun, and, at the age of 2.3 billion years, has expanded to 10 times the Sun's radius.
It has a relatively high proper motion, traversing the celestial sphere at the rate of per year. This star is 425 million years old with a stellar classification of A5 IV-V, indicating the spectrum displays mixed traits of an A-type main-sequence star and an older subgiant star. It is spinning rapidly with a projected rotational velocity of 135 km/s, which is giving the star an oblate shape with an equatorial bulge that is 6% larger than the polar radius. The star has double the mass of the Sun and about 1.9 times the Sun's radius.
Beam park is a radar mode used for space surveillance, particularly tracking space debris. In beam-park mode, a radar beam is kept in a fixed direction with respect to the Earth, while objects passing through the beam are tracked. In 24 hours, as a result of the Earth’s rotation, the radar effectively scans a narrow strip through 360° of the celestial sphere. The scattered waves are detected by a receiver and the measurements obtained during the observations can be used to determine object radar cross-section, time of peak occurrence, polarization ratio, doppler shift and object rotation.
In Mithraic images, Mithras either represents the sun, or is a close friend of the sun god Helios or Sol Invictus (Latin: the invincible sun) with whom Mithras dines. So attendants Cautes and Cautopates are supposed to represent the stations of sunrise and sunset respectively, or perhaps the spring and autumn equinoxes, or equivalently the ascending (spring) and descending (autumnal) nodes of the Sun's apparent path on the celestial sphere. If eclipses of the sun and moon formed part of Mithraic symbolism, they could also represent the ascending and descending nodes where the Moon crosses the ecliptic.
Einstein, recipient of the Nobel Prize in Physics in 1921, though not for his development of general relativity. The theory behind the experiment concerns the predicted deflection of light by the Sun. The first observation of light deflection was performed by noting the change in position of stars as they passed near the Sun on the celestial sphere. The approximate angular deflection δφ for a massless particle coming in from infinity and going back out to infinity is given by the following formula:For the derivation of this formula, see the article on the Two-body problem in general relativity.
Therefore, there must be an eternal circular motion and > this is confirmed by the fixed stars which are moved by the eternal actual > substance that's purely actual. In Aristotle's estimation, an explanation without the temporal actuality and potentiality of an infinite locomotive chain is required for an eternal cosmos with neither beginning nor end: an unmoved eternal substance for whom the Primum MobileThe outermost celestial sphere, for Aristotle, the sphere of fixed stars. turns diurnally and whereby all terrestrial cycles are driven: day and night, the seasons of the year, the transformation of the elements, and the nature of plants and animals.
The style is usually aligned parallel to the axis of the celestial sphere, and therefore is aligned with the local geographical meridian. In some sundial designs, only a point-like feature, such as the tip of the style, is used to determine the time and date; this point-like feature is known as the sundial's nodus. Some sundials use both a style and a nodus to determine the time and date. The gnomon is usually fixed relative to the dial face, but not always; in some designs such as the analemmatic sundial, the style is moved according to the month.
Hipparchus concluded that the equinoxes were moving ("precessing") through the zodiac, and that the rate of precession was not less than 1° in a century, in other words, completing a full cycle in no more than 36000 years. Virtually all of the writings of Hipparchus are lost, including his work on precession. They are mentioned by Ptolemy, who explains precession as the rotation of the celestial sphere around a motionless Earth. It is reasonable to presume that Hipparchus, similarly to Ptolemy, thought of precession in geocentric terms as a motion of the heavens, rather than of the Earth.
The Masjid-i Jehan Numa ( the 'World-reflecting Mosque' or "Mosque of the Celestial Sphere"), commonly known as the Jama Masjid of Delhi, is one of the largest mosques in India. It was built by the Mughal Emperor Shah Jahan between 1650 and 1656 at a cost of one million rupees, and was inaugurated by Imam Syed Abdul Ghafoor Shah Bukhari from Bukhara. The mosque was completed in 1656 AD with three great gates and two 40 metres high minarets constructed with strips of red sandstone and white marble. The courtyard can accommodate more than 25000 people.
He argues that the cult was a religious response to Hipparchus's discovery of precession, which – from the ancient geocentric perspective – amounted to the discovery that the entire cosmos (i.e., the outermost celestial sphere of the fixed stars) was moving in a previously unknown way. Ulansey's analysis is based on the so-called tauroctony: The image of Mithras killing a bull that was placed at the center of every Mithraic temple. In the standard tauroctony, Mithras and the bull are accompanied by a dog, a snake, a raven, a scorpion and two identical young men, with torches.
High-energy gamma rays (>50MeV photons) were finally discovered in the primary cosmic radiation by an MIT experiment carried on the OSO-3 satellite in 1967. Components of both galactic and extra-galactic origins were separately identified at intensities much less than 1% of the primary charged particles. Since then, numerous satellite gamma-ray observatories have mapped the gamma-ray sky. The most recent is the Fermi Observatory, which has produced a map showing a narrow band of gamma ray intensity produced in discrete and diffuse sources in our galaxy, and numerous point-like extra-galactic sources distributed over the celestial sphere.
The period of the Moon's orbit as defined with respect to the celestial sphere of apparently fixed stars (the International Celestial Reference Frame; ICRF) is known as a sidereal month because it is the time it takes the Moon to return to a similar position among the stars (): days (27 d 7 h 43 m 11.6 s). This type of month has been observed among cultures in the Middle East, India, and China in the following way: they divided the sky into 27 or 28 lunar mansions, one for each day of the month, identified by the prominent star(s) in them.
The system has a relatively high rate of proper motion, traversing the celestial sphere at the rate of along a position angle of 136°. The stellar classification of the visible component is K2+ IIIb, which matches an evolved K-type giant star. It is a red clump star, which indicates it is on the horizontal branch and is generating energy through helium fusion at its core. The interferometry- measured angular diameter of the primary, after correcting for limb darkening, is , which, at its estimated distance, equates to a physical radius of about 10.6 times the radius of the Sun.
The latitude of the Earth's equator is, by definition, 0° (zero degrees) of arc. The equator is one of the five notable circles of latitude on Earth; the other four are both polar circles (the Arctic Circle and the Antarctic Circle) and both tropical circles (the Tropic of Cancer and the Tropic of Capricorn). The equator is the only line of latitude which is also a great circle—that is, one whose plane passes through the center of the globe. The plane of Earth's equator, when projected outwards to the celestial sphere, defines the celestial equator.
14 Vulpeculae is a single, yellow-white hued star in the northern constellation of Vulpecula and proximate to the Dumbbell Nebula (M 27) on the celestial sphere, although actually much closer to the Earth. It is a dim star that is faintly visible to the naked eye with an apparent visual magnitude of 5.68. The distance to 14 Vul, as determined from its annual parallax shift of , is around 160 light years. It is moving nearer with a heliocentric radial velocity of about −38 km/s, and will make its closest approach in a million years when comes to within about .
Over the entrance door is a fresco with the image of Our Lady, and over the windows are frescos of St. Vladimir and St. Constantine the Great. Distribution of images of saints have cast their importance in the history of salvation. Characters of Old Testament prophets, according to the Byzantine tradition, are found on the inner side of the main drum, which was indicative of their mediation between earth and celestial sphere. In contrast, figures of saints connected with the history of Russia would remind you of the status of the Orthodox Church as the state religion in that country.
The Sun as seen from Lamlash, Scotland () on 3 January 2010, at 8:53 a.m. local time The position of the Sun in the sky is a function of both the time and the geographic location of observation on Earth's surface. As Earth orbits the Sun over the course of a year, the Sun appears to move with respect to the fixed stars on the celestial sphere, along a circular path called the ecliptic. Earth's rotation about its axis causes diurnal motion, so that the Sun appears to move across the sky in a Sun path that depends on the observer's geographic latitude.
The building has a monumental, 36 m high facade, in a style that mixes 20th- century architecture and Neoclassicism; it is realized in marble and travertine and decorated with sculptures by Leone Lodi and Geminiano Cibau. The main room of the Palace, called "sala delle grida" ("cries room") as businessmen would shout their offers to buy and sell, is lighted by a large net, affixed to the ceiling, which reproduces the constellations in the celestial sphere. Since the 1990s, all business is done remotely via the network, and the room has lost its original function; it is now mostly used to house conferences.
Because Earth's rotational axis is not perpendicular to its orbital plane, Earth's equatorial plane is not coplanar with the ecliptic plane, but is inclined to it by an angle of about 23.4°, which is known as the obliquity of the ecliptic.Explanatory Supplement (1992), p. 733 If the equator is projected outward to the celestial sphere, forming the celestial equator, it crosses the ecliptic at two points known as the equinoxes. The Sun, in its apparent motion along the ecliptic, crosses the celestial equator at these points, one from south to north, the other from north to south.
The Sun at the moment of the March equinox in 2019, when the center of the solar disk contacts the celestial equator (the imaginary line on the celestial sphere above Earth's equator) from south to north. An equinox is commonly regarded as the instant of time when the plane (extended indefinitely in all directions) of Earth's equator passes through the geometric center of the Sun's disk. This occurs twice each year, around 20 March and 23 September. In other words, it is the moment at which the center of the visible Sun is directly above the equator.
The tradition of thought which appears in all of these systems of the universe, even with their divergent mechanisms, is the presence of a celestial sphere which contains the fixed stars. Ptolemy was influential with his heavily mathematical work, The Almagest, which attempts to explain the peculiarity of stars that moved. These "wandering stars", planets, moved across the background of fixed stars which were spread along a sphere surrounding encompassing the universe. Later on, contemporary astronomers and mathematicians, like Copernicus challenged the long-standing view of geocentrism and constructed a Sun-centered universe, this being known as the heliocentric system.
The painting's composition has similarities to The Last Judgment triptych in Vienna and The Garden of Earthly Delights: both show the Garden of Eden in the left panel and the Hell at right. Like in other contemporary Flemish triptychs, the shutters are externally painted in grisaille with an Coronation with Thorns. In the central panel is Christ as a judge within a celestial sphere, flanked by angels who are playing the Trumpets of Last Judgement, and by the apostles. Below him is the punishment of sinners which, like the Last Judgement of Vienna, continues in the Hell depiction at right.
Planetarium software is application software that allows a user to simulate the celestial sphere at any time of day, especially at night, on a computer. Such applications can be as rudimentary as displaying a star chart or sky map for a specific time and location, or as complex as rendering photorealistic views of the sky. While some planetarium software is meant to be used exclusively on a personal computer, some applications can be used to interface with and control telescopes or planetarium projectors. Optional features may include inserting the orbital elements of comets and other newly discovered bodies for display.
30 Vulpeculae is a binary star system in the northern constellation of Vulpecula, located mid-way between Epsilon Cygni and a diamond-shaped asterism in Delphinus. It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.91. The system is located approximately 350 light years away from the Sun based on parallax, and is drifting further away with a mean radial velocity of +30 km/s. The system has a relatively high proper motion, traversing the celestial sphere at the rate of 0.186 arc seconds per annum.
The term Uttarāyaṇa (commonly Uttarayan) is derived from two different Sanskrit words "uttara" (North) and "ayana" (movement) thus indicating a semantic of the northward movement of the Earth on the celestial sphere. This movement begins to occur a day after the winter solstice in December which occurs around 22 December and continues for a six-month period through to the summer solstice around June 21 (dates vary ). This difference is because the solstices are continually precessing at a rate of 50 arcseconds / year due to the precession of the equinoxes, i.e. this difference is the difference between the sidereal and tropical zodiacs.
As with van der Weyden's Braque Triptych, the background landscape and arrangements of figures extend across individual panels of the lower register to the extent that the separations between panels are ignored.Jacobs (2011), 97 There are instances of figures painted across two adjoining panels,Jacobs (2011), 98 whereas Christ and St Michael are enclosed within the single central panel, giving emphasis to the iconography.Blum (1969), 43 The celestial sphere, towards which the saved move, is dramatically presented with a "radiant gold background, spanning almost the entire width of the altarpiece". The lower register presents Earth and contains the gates to Heaven and Hell.
HR 7955 is a binary star system in the northern circumpolar constellation of Cepheus, near the constellation border with Cygnus. It has a yellow-white hue and is faintly visible to the naked eye with a combined apparent visual magnitude of 4.51. The system is located at a distance of 89 light-years (27.3 parsecs) from the Sun, based on parallax. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.243 arc seconds per annum, and is drifting closer to the Sun with a radial velocity of -33 km/s.
She is suspected to hold feelings for Sekai, and often offers to build Sekai a new Gunpla, which appears to be her way of expressing friendship or camaraderie, as she also offers to do the same for her teammates. By episode 25, she had finally followed through in helping Sekai make his own Gunpla: the Kamiki Burning Gundam. Both Fumina and Gyanko are highly suspicious of Shia, and they become jealous when seeing Sekai with her. ; : :Gunpla: CB-9696G/C/T Reversible Gundam :A former PPSE designer and coach of Tatsuya, he now coaches Celestial Sphere.
In conformal geometry, the ambient construction refers to a construction of Charles Fefferman and Robin GrahamFefferman, C. and Graham, R. "Conformal invariants", in Élie Cartan et les Mathématiques d'Aujourdui, Asterisque (1985), 95-116. for which a conformal manifold of dimension n is realized (ambiently) as the boundary of a certain Poincaré manifold, or alternatively as the celestial sphere of a certain pseudo-Riemannian manifold. The ambient construction is canonical in the sense that it is performed only using the conformal class of the metric: it is conformally invariant. However, the construction only works asymptotically, up to a certain order of approximation.
The Celestial Sphere Woodrow Wilson Memorial, by Paul Manship, presented in 1939 to the League of Nations by the Woodrow Wilson Foundation and installed in Geneva. On April 16, 1922, Frank L. Polk announced on behalf of the Woodrow Wilson Foundation that the organization would make its awards internationally, not limiting prize winners to Americans. It would remain to the 15 member Board of Trustees to determine the size and frequency of such awards, Polk noted. An awards jury of 9 was decided upon late in 1923, headed by the elderly former President of Harvard College, Charles William Eliot.
Persian miniature depicting the artist's impression of heaven Similar to Jewish traditions such as the Talmud, the Qur'an and Hadith frequently mention the existence of seven samāwāt (سماوات), the plural of samāʾ (سماء), meaning 'heaven, sky, celestial sphere', and cognate with Hebrew shamāyim (שמים). Some of the verses in the Qur'an mentioning the samaawat are , , . Sidrat al- Muntaha, a large enigmatic Lote tree, marks the end of the seventh heaven and the utmost extremity for all of God's creatures and heavenly knowledge.Abdullah, Yusuf Ali (1946) The Holy Qur-an: Text, Translation and Commentary, Qatar National Printing Press. p.
This coincides with the precessional orbit of moon or the ~18-year rotational cycle of the lunar ascending and descending nodes on the earth's ecliptic plane. Ketu rules the Scorpio zodiac sign together with Mangala Astronomically, Rahu and Ketu denote the points of intersection of the paths of the Sun and the Moon as they move on the celestial sphere. Therefore, Rahu and Ketu are respectively called the north and the south lunar nodes. The fact that eclipses occur when the Sun and the Moon are at one of these points gives rise to the understanding of swallowing of the Sun and the Moon by the snake.
Wolf 359 first came to the attention of astronomers because of the relatively high rate of transverse motion against the background, known as the proper motion. A high rate of proper motion can indicate that a star is located nearby, as more distant stars must move at higher velocities in order to achieve the same rate of angular travel across the celestial sphere. The proper motion of Wolf 359 was first measured in 1917 by German astronomer Max Wolf, with the aid of astrophotography. In 1919 he published a catalog of over one thousand stars with high proper motions, including this one, that are still identified by his name.
Its spectral class is O9.5Ve, meaning that it is an O-type main-sequence star. The Flaming Star Nebula, is located near IC 410 in the celestial sphere. IC 410 obtained its name from its appearance in long exposure astrophotographs; it has extensive filaments that make AE Aurigae appear to be on fire. There are four Mira variable stars in Auriga: R Aurigae, UV Aurigae, U Aurigae, and X Aurigae, all of which are type M stars. More specifically, R Aurigae is of type M7III, UV Aurigae is of type C6 (a carbon star), U Aurigae is of type M9, and X Aurigae is of type K2.
Turkish geographer, Mahmud al-Kashgari drew a world map on a linguistic basis, and later so did Piri Reis (Piri Reis map). Further, Islamic scholars translated and interpreted the earlier works of the Romans and the Greeks and established the House of Wisdom in Baghdad for this purpose. Abū Zayd al-Balkhī, originally from Balkh, founded the "Balkhī school" of terrestrial mapping in Baghdad. Suhrāb, a late tenth century Muslim geographer accompanied a book of geographical coordinates, with instructions for making a rectangular world map with equirectangular projection or cylindrical equidistant projection. Abu Rayhan Biruni (976–1048) first described a polar equi-azimuthal equidistant projection of the celestial sphere.
Planetary coordinate systems are defined relative to their mean axis of rotation and various definitions of longitude depending on the body. The longitude systems of most of those bodies with observable rigid surfaces have been defined by references to a surface feature such as a crater. The north pole is that pole of rotation that lies on the north side of the invariable plane of the solar system (near the ecliptic). The location of the prime meridian as well as the position of the body's north pole on the celestial sphere may vary with time due to precession of the axis of rotation of the planet (or satellite).
The star has a relatively high proper motion, traversing the celestial sphere at an angular rate of per year. In Chinese astronomy, 16 Virginis is called 謁者, Pinyin: Yèzhě, meaning Usher to the Court, because this star is marking itself and stand alone in Usher to the Court asterism, Supreme Palace enclosure mansion (see : Chinese constellation). This is an evolved K-type giant star with a stellar classification of , where the suffix notation denotes a mild underabundance of iron in the spectrum. It is a red clump giant, which indicates is on the horizontal branch generating energy via helium fusion at its core.
Three non-collinear points in space suffice to determine an orbital plane. A common example would be the positions of the centers of a massive body (host) and of an orbiting celestial body at two different times/points of its orbit. The orbital plane is defined in relation to a reference plane by two parameters: inclination (i) and longitude of the ascending node (Ω). By definition, the reference plane for the Solar System is usually considered to be Earth's orbital plane, which defines the ecliptic, the circular path on the celestial sphere that the Sun appears to follow over the course of a year.
GJ 1151 is a star located in the northern circumpolar constellation of Ursa Major at a distance of 26.2 light years from the Sun. It has a reddish hue and is too faint to be visible to the naked eye with an apparent visual magnitude of 14.0 The star is moving closer with a radial velocity of −36 km/s, and has a relatively large proper motion, traversing the celestial sphere at a rate of ·yr−1. This is a small red dwarf star of spectral type dM4.5. It is 2.5 billion years old and is spinning with a projected rotational velocity of 2.0 km/s.
5 Andromedae is moving further from the Sun with a radial velocity of +34 km/s. It has a relatively high proper motion, advancing across the celestial sphere at the rate of 0.151 arc seconds per year. This is an F-type main-sequence star with a stellar classification of F1 V. It is an estimated 603 million years old with a relatively high rate of spin, showing a projected rotational velocity of around 88 km/s. The star has 1.45 times the mass of the Sun and it is radiating 9.36 times the Sun's luminosity from its photosphere at an effective temperature of around 7,161 K.
The star is moving closer to the Earth with a heliocentric radial velocity of −40 km/s, and is predicted to come as close as in 259,000 years. It has a relatively high proper motion, traversing the celestial sphere at the rate of per year. This is an ordinary F-type main-sequence star with a stellar classification of F5 V. It is about 1.6 billion years old with an estimated 1.19 times the mass of the Sun and 1.44 times the Sun's radius. The star is radiating 2.9 times the Sun's luminosity from its photosphere at an effective temperature of around 6,274 K.
56 Andromedae, abbreviated 56 And, is a probable binary star system in the northern constellation of Andromeda. 56 Andromedae is the Flamsteed designation. It has a combined apparent visual magnitude of 5.69, which is just bright enough to be dimly visible to the naked eye under good seeing conditions. The distance to this system can be ascertained from its annual parallax shift, measured at with the Gaia space observatory, which yields a separation of 330 light years. It is moving further from the Earth with a heliocentric radial velocity of +62 km/s and is traversing the celestial sphere at a relatively high rate of per year.
The system has a relatively high proper motion, advancing across the celestial sphere at the rate of 0.272 arc seconds per annum. This is a single-lined spectroscopic binary with an orbital period of 9.2 years and an eccentricity of 0.3. Some early observations of the star gave it a subgiant luminosity class and it was published in the Bright Star Catalogue as spectral class F5 IV. More modern measurements identify the visible component as an F-type main-sequence star with a stellar classification of F5 V. The star is an estimated 2.9 billion years old with 1.3 times the mass of the Sun and 1.5 times the Sun's radius.
Ulugh Beg built an astronomical observatory near Samarkand in 1429 and wrote his work Zij-i-Sultani, which comprises the theories of astronomy and a catalogue of over 1000 stars with their precise positions on the celestial sphere. A long rivalry of Moghulistan with the Oirats for trade routes ended with its defeat by the Oirats in 1530. Babur, a Timurid ruler of Kabul, conquered most of India in 1526 and founded the Mughal Empire. The Mughal Empire fractured into several lesser states in the 18th and 19th century and later the capital of the former empire was conquered by the British Empire in 1858.
The only work of Geminus to survive is his Introduction to the Phenomena (), often just called the Isagoge. This introductory astronomy book, based on the works of earlier astronomers such as Hipparchus, was intended to teach astronomy for beginning students in the subject. In it, Geminus describes the zodiac and the motion of the Sun; the constellations; the celestial sphere; days and nights; the risings and settings of the zodiacal signs; luni-solar periods and their application to calendars; phases of the Moon; eclipses; star phases; terrestrial zones and geographical places; and the foolishness of making weather predictions by the stars.Evans, J., The History and Practice of Ancient Astronomy, page 91.
The crista itself is a circular piece that corresponds with the meridian of the celestial sphere, which has four quadrants inscribed along the edges, each starting at 0 degrees along the horizontal, and 90 degrees along the vertical. Adjacent, and locked with the crista at 23.5 degrees angle is the semis, which is a half- circle composed of two quadrants starting at 0 degrees along the vertical (relative to 23.5-degree placement) and 90 degrees at the horizontal. Finally, the last major component is the perpendicular, a free-hanging pendulum which measures the angle between the radial line of the Earth and the measured object using the semis.
An astrolabe consists of a disk, called the mater (mother), which is deep enough to hold one or more flat plates called tympans, or climates. A tympan is made for a specific latitude and is engraved with a stereographic projection of circles denoting azimuth and altitude and representing the portion of the celestial sphere above the local horizon. The rim of the mater is typically graduated into hours of time, degrees of arc, or both. Above the mater and tympan, the rete, a framework bearing a projection of the ecliptic plane and several pointers indicating the positions of the brightest stars, is free to rotate.
The sidereal hour angle (SHA) of a body on the celestial sphere is its angular distance west of the vernal equinox generally measured in degrees. An alternate definition is that SHA of a celestial body is the arc of the Equinoctial or the angle at the celestial pole contained between the celestial meridian of the First point of Aries and that through the body, measured westward from Aries. The SHA of a star changes slowly, and the SHA of a planet doesn't change very quickly, so SHA is a convenient way to list their positions in an almanac. SHA is often used in celestial navigation and navigational astronomy.
Since [x] ∈ Q, v · v = λ2 ≥ 0. The orthogonal space to (1,0,0,0,0), intersected with the Lie quadric, is the two dimensional celestial sphere S in Minkowski space-time. This is the Euclidean plane with an ideal point at infinity, which we take to be [0,0,0,0,1]: the finite points (x,y) in the plane are then represented by the points [v] = [0,x,y, −1, (x2+y2)/2]; note that v · v = 0, v · (1,0,0,0,0) = 0 and v · (0,0,0,0,1) = −1\. Hence points x = λ(1,0,0,0,0) + v on the Lie quadric with λ = 0 correspond to points in the Euclidean plane with an ideal point at infinity.
Tai Sui General#1 () The 12 signs of the Chinese zodiac are based on divisions of the Jovian orbital cycle, rather than—as with the western zodiac—the apparent motion of the sun relative to the celestial sphere. The star thought to oppose Jupiter during each year of the cycle was personified as a Heavenly General () or Cycle God. These were believed to assist the Jade Emperor in controlling the mortal world. Their number was later quintupled to 60, based on the combinations of the twelve divisions (reckoned using the earthly stems) with the five Chinese elements of fire, earth, metal, water, and wood.
In geography, the location of any point on the Earth can be identified using a geographic coordinate system. This system specifies the latitude and longitude of any location in terms of angles subtended at the centre of the Earth, using the equator and (usually) the Greenwich meridian as references. In astronomy, a given point on the celestial sphere (that is, the apparent position of an astronomical object) can be identified using any of several astronomical coordinate systems, where the references vary according to the particular system. Astronomers measure the angular separation of two stars by imagining two lines through the centre of the Earth, each intersecting one of the stars.
The ratio of the earth's distance from the sun to the height of the > firmament (outermost celestial sphere containing the stars) is so much > smaller than the ratio of the earth's radius to its distance from the sun > that the distance from the earth to the sun is imperceptible in comparison > with the height of the firmament. > 5\. Whatever motion appears in the firmament arises not from any motion of > the firmament, but from the earth's motion. The earth together with its > circumjacent elements performs a complete rotation on its fixed poles in a > daily motion, while the firmament and highest heaven abide unchanged.
Eta Cephei is a subgiant star with a stellar classification of K0 IV, which indicates it is exhausting the supply of hydrogen at its core and is in the process of evolving into a giant star. With 1.6 times the Sun's mass, at an age of 2.5 billion years it has reached a radius four times larger than the Sun and a luminosity ten times greater. It is radiating this energy from its outer atmosphere at an effective temperature of 4,950 K, giving it the orange-hued glow of a K-type star. Eta Cephei has a high proper motion across the celestial sphere and a large peculiar velocity of .
The angle- preserving symmetries of the two-sphere are described by the group of Möbius transformations PSL(2,C). With respect to this group, the sphere is equivalent to the usual Riemann sphere. The group PSL(2,C) is isomorphic to the (proper) Lorentz group, and its action on the two-sphere agrees with the action of the Lorentz group on the celestial sphere in Minkowski space. The analog of the spherical harmonics for the Lorentz group is given by the hypergeometric series; furthermore, the spherical harmonics can be re-expressed in terms of the hypergeometric series, as SO(3) = PSU(2) is a subgroup of PSL(2,C).
In classical antiquity, the seven classical planets or seven sacred luminaries are the seven moving astronomical objects in the sky visible to the naked eye: the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. The word planet comes from two related Greek words, πλάνης planēs (whence πλάνητες ἀστέρες planētes asteres "wandering stars, planets") and πλανήτης planētēs, both with the original meaning of "wanderer", expressing the fact that these objects move across the celestial sphere relative to the fixed stars.Classification of the Planets, . Greek astronomers such as Geminus and Ptolemy often divided the seven planets into the Sun, the Moon, and the five planets.
Kepler gave an alternative explanation of the Pythagoreans' "central fire" as the Sun, "as most sects purposely hid[e] their teachings". Heraclides of Pontus (4th century BC) said that the rotation of the Earth explained the apparent daily motion of the celestial sphere. It used to be thought that he believed Mercury and Venus to revolve around the Sun, which in turn (along with the other planets) revolves around the Earth. Macrobius Ambrosius Theodosius (AD 395–423) later described this as the "Egyptian System," stating that "it did not escape the skill of the Egyptians," though there is no other evidence it was known in ancient Egypt.
Cracow University's Collegium Novum From publication until about 1700, few astronomers were convinced by the Copernican system, though the work was relatively widely circulated (around 500 copies of the first and second editions have survived,Gingerich (2004), p.248 which is a large number by the scientific standards of the time). Few of Copernicus' contemporaries were ready to concede that the Earth actually moved. Even forty-five years after the publication of De Revolutionibus, the astronomer Tycho Brahe went so far as to construct a cosmology precisely equivalent to that of Copernicus, but with the Earth held fixed in the center of the celestial sphere instead of the Sun.
Celestial objects like quasars, super dense objects that lie far from Earth, emit electromagnetic waves in its full spectrum including radio waves. We can also hear the fall of a meteorite in a radio receiver; the falling object burns from friction with the Earth's atmosphere, ionizing surrounding gases and producing radio waves. Cosmic microwave background radiation (CMBR) from outer space, discovered by Arno Penzias and Robert Wilson, who later won the Nobel Prize for this discovery, is also a form of cosmic noise. CMBR is thought to be a relic of the Big Bang, and pervades the space almost homogeneously over the entire celestial sphere.
In addition to Bach scholarship, he acted as a publisher and editor of music from the 17th and 18th centuries. Among his works are A Lyke-Wake Dirge for chorus and orchestra (1925), and Among the Northumbrian Hills, free variations on an original theme for piano and string quartet (1922), both of which were published as part of the Carnegie Collection of British Music. Other works include The Celestial Sphere for chorus and orchestra, and Psalm CXXXIX. He also had a strong interest in folk music from his native Tyneside and Northumberland, championing the Northumbrian smallpipes; he published arrangements of folk songs, including choral versions of the "Keel Row", "Bobby Shaftoe", "Blow the Wind Southerly" and "Water of Tyne".
As late as 1650, P. Schirleus built a geocentric planetarium with the Sun as a planet, and with Mercury and Venus revolving around the Sun as its moons. At the court of William IV, Landgrave of Hesse-Kassel two complicated astronomic clocks were built in 1561 and 1563–1568. These use four sides to show the ecliptical positions of Sun, Mercury, Venus, Mars, Jupiter, Saturn, the Moon, Sun and Dragon (Nodes of the Moon) according to Ptolemy, a calendar, the sunrise and sunset, and an automated celestial sphere with an animated Sun symbol which, for the first time on a celestial globe, shows the real position of the Sun, including the equation of time.Lloyd (1958), pp. 46–57.
According to Plato, the Earth was a sphere, stationary at the center of the universe. The stars and planets were carried around the Earth on spheres or circles, arranged in the order (outwards from the center): Moon, Sun, Venus, Mercury, Mars, Jupiter, Saturn, fixed stars, with the fixed stars located on the celestial sphere. In his "Myth of Er", a section of the Republic, Plato describes the cosmos as the Spindle of Necessity, attended by the Sirens and turned by the three Fates. Eudoxus of Cnidus, who worked with Plato, developed a less mythical, more mathematical explanation of the planets' motion based on Plato's dictum stating that all phenomena in the heavens can be explained with uniform circular motion.
It is the only remaining astronomical clock from the Joseon Dynasty. The mechanism of the armillary sphere succeeded that of Sejong era's armillary sphere (Honŭi 渾儀, 1435) and celestial sphere (Honsang 渾象, 1435), and the Jade Clepsydra (Ongnu 玉漏, 1438)'s sun-carriage apparatus. Such mechanisms are similar to Ch'oe Yu-ji (崔攸之, 1603~1673)'s armillary sphere(1657). The structure of time going train and the mechanism of striking-release in the part of clock is influenced by the crown escapement which has been developed from 14th century, and is applied to gear system which had been improved until the middle of 17th century in Western-style clockwork.
16 Aurigae is a triple star system located 232 light years away from the Sun in the northern constellation of Auriga. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.547, and is located about 2/3 of the way from Capella toward Beta Tauri. It also lies in the midst of the Melotte 31 cluster, but is merely a line-of-sight interloper. The system has a relatively high proper motion, advancing across the celestial sphere at the rate of 0.166 arc seconds per annum, and is moving closer to the Earth with a heliocentric radial velocity of −28 km/s.
While the stars within some constellations appear correctly as they would from earth, other constellations are reversed left-to-right, as is the overall arrangement of the constellations on the ceiling. For example, Orion is correctly rendered, but the adjacent constellations Taurus and Gemini are reversed both internally and in their relation to Orion, with Taurus near Orion's raised arm where Gemini should be. There are various explanations that are often given for this error. One possible explanation is that the overall ceiling design might have been based on the medieval custom of depicting the sky as it would appear to God looking in at the celestial sphere from outside, but that would have reversed Orion as well.
Jansky finally determined that the "faint hiss" repeated on a cycle of 23 hours and 56 minutes. This period is the length of an astronomical sidereal day, the time it takes any "fixed" object located on the celestial sphere to come back to the same location in the sky. Thus Jansky suspected that the hiss originated outside of the Solar System, and by comparing his observations with optical astronomical maps, Jansky concluded that the radiation was coming from the Milky Way Galaxy and was strongest in the direction of the center of the galaxy, in the constellation of Sagittarius. An amateur radio operator, Grote Reber, was one of the pioneers of what became known as radio astronomy.
As a new Zoroaster, Dan carries his lover to the moon. No longer held back by the laws of physics, he rearranges the celestial sphere and the lunar landscape for Maria's pleasure, building her a heavenly abode, serviced by the angels and decorated with blue flowers; in this arrangement, Earth itself is a contemptible atom, consumed by hatred and war. Dan finds that the entire cosmos is his, except for the inaccessible "dome of God". He becomes obsessed with looking upon the divine countenance, and with reshaping the angels into instruments of his will; Dan begins to formulate a thought, that he himself may be God, and may not be remembering as much.
Angles and planes of a celestial sphere The shadows of trees are the shortest on Earth when the Sun is directly overhead (at the zenith). This happens only at solar noon on certain days in the tropics, where the trees' latitude and the Sun's declination are equal. The term zenith sometimes means the highest point, way, or level reached by a celestial body on its daily apparent path around a given point of observation. This sense of the word is often used to describe the position of the Sun ("The sun reached its zenith..."), but to an astronomer, the Sun does not have its own zenith and is at the zenith only if it is directly overhead.
At a given location during the course of a day, the Sun reaches not only its zenith but also its nadir, at the antipode of that location 12 hours from solar noon. In astronomy, the altitude in the horizontal coordinate system and the zenith angle are complementary angles, with the horizon perpendicular to the zenith. The astronomical meridian is also determined by the zenith, and is defined as a circle on the celestial sphere that passes through the zenith, nadir, and the celestial poles. A zenith telescope is a type of telescope designed to point straight up at or near the zenith, and used for precision measurement of star positions, to simplify telescope construction, or both.
On the other hand, points x with λ nonzero correspond to oriented circles (or oriented lines, which are circles through infinity) in the Euclidean plane. This is easier to see in terms of the celestial sphere S: the circle corresponding to [λ(1,0,0,0,0) + v] ∈ Q (with λ ≠ 0) is the set of points y ∈ S with y · v = 0. The circle is oriented because v/λ has a definite sign; [−λ(1,0,0,0,0) + v] represents the same circle with the opposite orientation. Thus the isometric reflection map x → x + 2 (x · (1,0,0,0,0)) (1,0,0,0,0) induces an involution ρ of the Lie quadric which reverses the orientation of circles and lines, and fixes the points of the plane (including infinity).
Based on observations between 1800 and 1880, Epsilon Eridani was found to have a large proper motion across the celestial sphere, which was estimated at three arcseconds per year (angular velocity). This movement implied it was relatively close to the Sun, making it a star of interest for the purpose of stellar parallax measurements. This process involves recording the position of Epsilon Eridani as Earth moves around the Sun, which allows a star's distance to be estimated. From 1881 to 1883, American astronomer William L. Elkin used a heliometer at the Royal Observatory at the Cape of Good Hope, South Africa, to compare the position of Epsilon Eridani with two nearby stars.
Cardinal directions or cardinal points may sometimes be extended to include elevation (altitude, depth): north, south, east, west, up and down, or mathematically the six directions of the x-, y-, and z-axes in three-dimensional space. Topographic maps include elevation, typically via contour lines. In astronomy, the cardinal points of an astronomical body as seen in the sky are four points defined by the directions towards which the celestial poles lie relative to the center of the disk of the object in the sky. A line (a great circle on the celestial sphere) from the center of the disk to the North celestial pole will intersect the edge of the body (the "limb") at the North point.
The duration of the planetary revolutions during a mahayuga is given as 4.32 million years. 2\. Ganitapada (33 verses): covering mensuration (kṣetra vyāvahāra); arithmetic and geometric progressions; gnomon/shadows (shanku- chhAyA); and simple, quadratic, simultaneous, and indeterminate equations (Kuṭṭaka). 3\. Kalakriyapada (25 verses): different units of time and a method for determining the positions of planets for a given day, calculations concerning the intercalary month (adhikamAsa), kShaya-tithis, and a seven-day week with names for the days of week. 4\. Golapada (50 verses): Geometric/trigonometric aspects of the celestial sphere, features of the ecliptic, celestial equator, node, shape of the earth, cause of day and night, rising of zodiacal signs on horizon, etc.
Among the other circuits new to the series are Willow Springs International Motorsports Park, Ascari Race Resort, and ones based in a sports stadium, in addition to several ones based in the Matterhorn, including the one near Riffelsee. As well as some tracks featuring variable weather and time of day, there is also a dynamic celestial sphere, so that stars in the night sky have accurate positions. With this, there is also a feature where players can drive at Hadley Rille on the moon with the Lunar Rover. The Top Gear test track, which appeared in Gran Turismo 5, doesn't return in the game due to the show's partnership with the Forza Motorsport franchise for the Xbox consoles.
Thus the circle was aligned with the local vertical or plumb line, which is deflected slightly from the normal, or line perpendicular, to the reference ellipsoid used to define geodetic latitude and longitude in the International Terrestrial Reference Frame (which is nearly the same as the WGS-84 system used by GPS). While the local vertical defined at the Airy transit circle still points to the modern celestial meridian (the intersection of the prime meridian plane with the celestial sphere), it does not pass through the Earth's rotation axis. As a result of this, the ITRF zero meridian, defined by a plane passing through the Earth's rotation axis, is 102.478 metres to the east of the prime meridian. A 2015 analysis by Malys et al.
The Chinese had multiple theories of the structure of the universe. The first theory is the Gaitian (celestial lid) theory, mentioned in an old mathematical text called Zhou bei suan jing in 100 BCE, in which the Earth is within the heaven, where the heaven acts as a dome or a lid. The second theory is the Huntian (Celestial sphere) theory during 100 BCE. This theory claims that the Earth floats on the water that the Heaven contains, which was accepted as the default theory until 200 AD. The Xuanye (Ubiquitous darkness) theory attempts to simplify the structure by implying that the Sun, Moon and the stars are just a highly dense vapour that floats freely in space with no periodic motion.
The first successful published direct measurements of an object at interstellar distances were undertaken by German astronomer Friedrich Wilhelm Bessel in 1838, who used this approach to calculate the 3.5-parsec distance of 61 Cygni. Stellar parallax motion from annual parallax The parallax of a star is defined as half of the angular distance that a star appears to move relative to the celestial sphere as Earth orbits the Sun. Equivalently, it is the subtended angle, from that star's perspective, of the semimajor axis of the Earth's orbit. The star, the Sun and the Earth form the corners of an imaginary right triangle in space: the right angle is the corner at the Sun, and the corner at the star is the parallax angle.
Diagram illustrating the definition of the hour circle of a star In astronomy, the hour circle, which together with declination and distance (from the planet's centre of mass) determines the location of any celestial object, is the great circle through the object and the two celestial poles. As such, it is a higher concept than the meridian as defined in astronomy, which takes account of the terrain and depth to the centre of Earth at a ground observer's location. The hour circles, specifically, are perfect circles perpendicular (at right angles) to the celestial equator. By contrast, the declination of an object viewed on the celestial sphere is the angle of that object to/from the celestial equator (thus ranging from +90° to −90°).
This rapid variation meant that the energy generation must take place over a relatively small region of roughly ,This is the distance light can travel in a third of a second. as the speed of light restricts communication between more distant regions. For a size comparison, the diameter of the Sun is about . In April–May 1971, Luc Braes and George K. Miley from Leiden Observatory, and independently Robert M. Hjellming and Campbell Wade at the National Radio Astronomy Observatory, detected radio emission from Cygnus X-1, and their accurate radio position pinpointed the X-ray source to the star AGK2 +35 1910 = HDE 226868. On the celestial sphere, this star lies about half a degree from the 4th-magnitude star Eta Cygni.
An analemma with solar declination and equation of time to the same scale An analemma is a diagram that shows the annual variation of the Sun's position on the celestial sphere, relative to its mean position, as seen from a fixed location on Earth. (The word analemma is also occasionally, but rarely, used in other contexts.) It can be considered as an image of the Sun's apparent motion during a year, which resembles a figure-8. An analemma can be pictured by superimposing photographs taken at the same time of day, a few days apart for a year. An analemma can also be considered as a graph of the Sun's declination, usually plotted vertically, against the equation of time, plotted horizontally.
Why the number nine is used has also been of concern to some. The number nine is seen in Taoist divination as the perfect number for yang/yo, the “bright side” when determining the individual hexagram lines according to the I-ching (Book of Changes). Some have suggested that the number nine refers to the nine planets, that the Taoist believe directly influence human destiny, or to the seven stars of the Big Dipper (Northern Seven Stars) plus the two attendant/guardian stars which Taoist believe is the gateway to heaven, and which each star is a Taoist deity. The Imperial Palace had nine halls, the celestial sphere has nine divisions, both in Buddhism and Taoism, heaven is 'nine enclosures' (chiu ch'ung).
Pre-recorded and live presentation formats are possible. Live format are preferred by many venues because a live expert presenter can answer on-the-spot questions raised by the audience. Since the early 1990s, fully featured 3-D digital planetaria have added an extra degree of freedom to a presenter giving a show because they allow simulation of the view from any point in space, not only the earth-bound view which we are most familiar with. This new virtual reality capability to travel through the universe provides important educational benefits because it vividly conveys that space has depth, helping audiences to leave behind the ancient misconception that the stars are stuck on the inside of a giant celestial sphere and instead to understand the true layout of the solar system and beyond.
Water, flowing into scoops, turned a wheel automatically, > rotating it one complete revolution in one day and night. Besides this, > there were two rings fitted around the celestial sphere outside, having the > sun and moon threaded on them, and these were made to move in circling orbit > ... And they made a wooden casing the surface of which represented the > horizon, since the instrument was half sunk in it. It permitted the exact > determinations of the time of dawns and dusks, full and new moons, tarrying > and hurrying. Moreover, there were two wooden jacks standing on the horizon > surface, having one a bell and the other a drum in front of it, the bell > being struck automatically to indicate the hours, and the drum being beaten > automatically to indicate the quarters.
A third superbly preserved zodiac mosaic was discovered in the Severus synagogue in the ancient resort town of Hammat Tiberias. In the center of the 4th-century mosaic the Sun god, Helios sits in his chariot holding the celestial sphere and a whip. Nine of the 12 signs of the zodiac survived intact. Another panel shows the Ark of Covenant and Jewish cultic objects used in the Temple at Jerusalem. In 1936, a synagogue was excavated in Jericho which was named Shalom Al Yisrael Synagogue after an inscription on its mosaic floor ("Peace on Israel"). It appears to have been in use from the 5th to 8th centuries and contained a big mosaic on the floor with drawings of the Ark of the Covenant, the Menorah, a Shofar and a Lulav.
Jost Bürgi and Antonius Eisenhoit: Armillary sphere with astronomical clock, made in 1585 in Kassel, now at Nordiska Museet in Stockholm An armillary sphere (variations are known as spherical astrolabe, armilla, or armil) is a model of objects in the sky (on the celestial sphere), consisting of a spherical framework of rings, centred on Earth or the Sun, that represent lines of celestial longitude and latitude and other astronomically important features, such as the ecliptic. As such, it differs from a celestial globe, which is a smooth sphere whose principal purpose is to map the constellations. It was invented separately in ancient Greece and ancient China, with later use in the Islamic world and Medieval Europe. With the Earth as center, an armillary sphere is known as Ptolemaic.
Even following the adoption of Copernicus's heliocentric model of the universe, new versions of the celestial sphere model were introduced, with the planetary spheres following this sequence from the central Sun: Mercury, Venus, Earth-Moon, Mars, Jupiter and Saturn. Mainstream belief in the theory of celestial spheres did not survive the Scientific Revolution. In the early 1600s, Kepler continued to discuss celestial spheres, although he did not consider that the planets were carried by the spheres but held that they moved in elliptical paths described by Kepler's laws of planetary motion. In the late 1600s, Greek and medieval theories concerning the motion of terrestrial and celestial objects were replaced by Newton's law of universal gravitation and Newtonian mechanics, which explain how Kepler's laws arise from the gravitational attraction between bodies.
Water, flowing into scoops, turned a wheel automatically, > rotating it one complete revolution in one day and night. Besides this, > there were two rings fitted around the celestial sphere outside, having the > sun and moon threaded on them, and these were made to move in circling orbit > ... And they made a wooden casing the surface of which represented the > horizon, since the instrument was half sunk in it. It permitted the exact > determinations of the time of dawns and dusks, full and new moons, tarrying > and hurrying. Moreover, there were two wooden jacks standing on the horizon > surface, having one a bell and the other a drum in front of it, the bell > being struck automatically to indicate the hours, and the drum being beaten > automatically to indicate the quarters.
Named for the constellation of Aries, it is one of the two points on the celestial sphere at which the celestial equator crosses the ecliptic, the other being the First Point of Libra, located exactly 180° from it. Due to precession of the equinoxes since the position was originally named in antiquity, the position of the Sun on the March equinox is now in Pisces, while that on the September equinox is in Virgo (as of J2000). Along its yearly path through the zodiac, the Sun meets the celestial equator from south to north at the First Point of Aries, and from north to south at the First Point of Libra. The First Point of Aries is considered to be the celestial "prime meridian" from which right ascension is calculated.
However, the exact value of these new units (zhang, chi and cun) was never stipulated, but can be deduced by the context in which they are used. For example, the spectacular passing of Halley's comet in 837 indicates that the tail of the comet measured 8 zhang. Even if it is not possible to know the angular size of the comet at the time it passed, it is certain that 8 zhang correspond to 180 degrees at the most (maximum visible angle on the celestial sphere), which means that one zhang can hardly exceed 20 degrees, and therefore one cun cannot exceed 0.2 degrees. A more rigorous estimation was made from 1972 on the basis of references of minimal separations expressed in chi or cun between two stars in the case of various conjunctions.
In the book's preface, Velikovsky summarizes his arguments: :Worlds in Collision is a book of wars in the celestial sphere that took place in historical times. In these wars the planet Earth participated too. [...] The historical-cosmological story of this book is based in the evidence of historical texts of many people around the globe, on classical literature, on epics of the northern races, on sacred books of the peoples of the Orient and Occident, on traditions and folklore of primitive peoples, on old astronomical inscriptions and charts, on archaeological finds, and also on geological and paleontological material. The book proposes that around the 15th century BCE, Venus was ejected from Jupiter as a comet or comet-like object and subsequently passed near Earth, though an actual collision with the Earth is not mentioned.
A "little astrolabe", or "plane astrolabe", is a kind of astrolabe that used stereographic projection of the celestial sphere to represent the heavens on a plane surface, as opposed to an armillary sphere, which was globe-shaped. Armillary spheres were large and normally used for display, whereas a plane astrolabe was portable and could be used for practical measurements. The statement from Synesius's letter has sometimes been wrongly interpreted to mean that Hypatia invented the plane astrolabe herself, but the plane astrolabe is known to have been in use at least 500 years before Hypatia was born. Hypatia may have learned how to construct a plane astrolabe from her father Theon, who had written two treatises on astrolabes: one entitled Memoirs on the Little Astrolabe and another study on the armillary sphere in Ptolemy's Almagest.
In Book Two, Kircher devoted much care to demonstrating that Nimrod's project to build a tower to touch the heavens was physically impossible to achieve, and would have been disastrous for the planet if it had. He explained that the distance from the earth to the lowest celestial sphere, that of the Moon, was twenty- five earth diameters. There were not enough building materials in the world to construct a tower so high, and if it had been built it would have pulled the entire planet over out of its equilibrium at the centre of the universe, causing darkness and extreme climate change in many parts of the world. In addition to this, he offered an illustrated survey of the wonders of the ancient world, including the pyramids of Egypt, the labyrinth of Crete and the colossus of Rhodes.
Three Chinese documents indicate that the guest star was located "perhaps a few inches" South-East of Tianguan. Song Shi and Song Huiyao stipulate that it "was standing guard" for the asterism, corresponding to the star ζ Tauri. The "South-East" orientation has a simple astronomical meaning, the celestial sphere having, like the Earth's globe, both north and south celestial poles, the "South-East" direction thus corresponding to a "bottom- left" location in relation to the reference object (in this case, the star ζ Tauri) when it appears at the South. However, this "South-East" direction has long left modern astronomers perplexed in the context of this event: the logical remnant of the supernova corresponding to the guest star is the Crab Nebula, but it is not situated to the southeast of ζ Tauri, rather in the opposite direction, to the northwest.
Sun and planets at local apparent noon (Ecliptic in red, Sun and Mercury in yellow, Venus in white, Mars in red, Jupiter in yellow with red spot, Saturn in white with rings). Even if the Earth's orbit were circular, the perceived motion of the Sun along our celestial equator would still not be uniform. This is a consequence of the tilt of the Earth's rotational axis with respect to the plane of its orbit, or equivalently, the tilt of the ecliptic (the path the Sun appears to take in the celestial sphere) with respect to the celestial equator. The projection of this motion onto our celestial equator, along which "clock time" is measured, is a maximum at the solstices, when the yearly movement of the Sun is parallel to the equator (causing amplification of perceived speed) and yields mainly a change in right ascension.
These heavenly bodies, namely the earth and planets, revolved around a central point in Philolaus's system, his could not be called a Heliocentric "solar system", because the central point which the earth and planets revolved around was not the sun, but the so-called Central Fire. This Fire was not visible from the surface of Earth—or at least not from the hemisphere Greece was located in. However, it has been pointed out that Stobaeus betrays a tendency to confound the dogmas of the early Ionian philosophers, and occasionally mixes up Platonism with Pythagoreanism. According to Eudemus, a pupil of Aristotle, the early Pythagoreans were the first to find the order of the planets visible to the naked eye. While Eudemus doesn’t provide the order, it is assumed to be moon – sun – Venus – Mercury – Mars – Jupiter – Saturn – celestial sphere, based on the "correct" order accepted in the time of Eudemus.
The spectrum of this star matches a stellar classification of G8 II-III, with the luminosity class notation 'II-III' indicating it shows some traits of both a giant star and a bright giant. At this evolutionary stage, the atmosphere has expanded to almost thirteen times the radius of the Sun and the outer envelope has an effective temperature of 5,196 K. X-ray emission has been detected from this star, with an estimated luminosity of . Alpha Reticuli has a 12th-magnitude visual companion, CCDM J04144-6228B, at an angular separation of 48 arcseconds away along a position angle of 355°. Since the two stars share a common proper motion across the celestial sphere, it is possible that Alpha Reticuli, rather than being solitary, may instead be the primary component of a binary star system with an orbital period of, at least, 60,000 years.
If marked to show the position of the Sun on it at fairly regular intervals (such as the 1st, 11th, and 21st days of every calendar month) the analemma summarises the apparent motion of the Sun, relative to its mean position, throughout the year. A date-marked diagram of the analemma, with equal scales in both north–south and east–west directions, can be used as a tool to estimate quantities such as the times of sunrise and sunset, which depend on the Sun's position. Generally, making these estimates depends on visualizing the analemma as a rigid structure in the sky, which moves around the Earth at constant speed so it rises and sets once a day, with the Sun slowly moving around it once a year. Some approximations are involved in the process, chiefly the use of a plane diagram to represent things on the celestial sphere, and the use of drawing and measurement instead of numerical calculation.
There is no precise definition of this term other than that it certainly comprehends the disciplines of geography and astronomy but at that time it would also include astrology and chronology (as a history of the world from the creation). All of these were among Mercator's accomplishments but his patron's first call on his services was as a mundane surveyor of the disputed boundary between the Duke's territory of the County of Mark and the Duchy of Westphalia. Astronomical clock with rotating globes Around this time Mercator also received and executed a very special order for the Holy Roman Emperor a pair of small globes, the inner ("fist-size") Earth was made of wood and the outer celestial sphere was made of blown crystal glass engraved with diamond and inlaid with gold. He presented them to the Emperor in Brussels who awarded him the title Imperatoris domesticus (a member of the Imperial household).
The huntian theory, as mentioned by Western Han dynasty astronomer Luoxia Hong (fl. 140-104 BC) and fully described by the Eastern Han dynasty polymath scientist and statesman Zhang Heng (78-139 AD), insisted that the heavens were spherical and that the earth was like an egg yolk at its center.Needham and Ling (1995), pp. 216-217. Yu Xi's ideas about the infinity of outer space seem to echo Zhang's ideas of endless space even beyond the celestial sphere. Although mainstream Chinese science before European influence in the 17th century surmised that the Earth was flat and square-shaped, some scholars, such as Song dynasty mathematician Li Ye (1192-1279 AD), proposed the idea that it was spherical like the heavens.Needham and Ling (1995), pp. 498-499. The acceptance of a spherical earth can be seen in the astronomical and geographical treatise Gezhicao (格致草) written in 1648 by Xiong Mingyu (熊明遇).Needham and Ling (1995), p. 499.
Instead, Arabian and Persian cartography followed Al-Khwārizmī in adopting a rectangular projection, shifting Ptolemy's Prime Meridian several degrees eastward, and modifying many of Ptolemy's geographical coordinates. Having received Greek writings directly and without Latin intermediation, Arabian and Persian geographers made no use of T-O maps. In the 9th century, the Persian mathematician and geographer, Habash al-Hasib al-Marwazi, employed spherical trigonometry and map projection methods in order to convert polar coordinates to a different coordinate system centred on a specific point on the sphere, in this the Qibla, the direction to Mecca. Abū Rayhān Bīrūnī (973–1048) later developed ideas which are seen as an anticipation of the polar coordinate system. Around 1025, he describes a polar equi-azimuthal equidistant projection of the celestial sphere. However, this type of projection had been used in ancient Egyptian star-maps and was not to be fully developed until the 15 and 16th centuries.
" Ibn al-Haytham, in his Book of Optics (1021), was also the first to discover that the celestial spheres do not consist of solid matter, and he also discovered that the heavens are less dense than the air. These views were later repeated by Witelo and had a significant influence on the Copernican and Tychonic systems of astronomy. In the 12th century, Fakhr al-Din al-Razi participated in the debate among Islamic scholars over whether the celestial spheres or orbits (falak) are "to be considered as real, concrete physical bodies" or "merely the abstract circles in the heavens traced out year in and year out by the various stars and planets." He points out that many astronomers prefer to see them as solid spheres "on which the stars turn," while others, such as the Islamic scholar Dahhak, view the celestial sphere as "not a body but merely the abstract orbit traced by the stars.
An extended X-ray source centered at 1300+28 in the direction of the Coma cluster of galaxies was reported before August 1966. This X-ray observation was performed by balloon, but the source was not detected in the sounding rocket flight launched by the X-ray astronomy group at the Naval Research Laboratory on November 25, 1964. A strong X-ray source was observed by the X-ray observatory satellite Uhuru close to the center of the Coma cluster and this source was suggested to be designated Coma X-1. The Coma cluster contains about 800 galaxies within a 100 x 100 arc-min area of the celestial sphere. The source near the center at RA (1950) 12h56m ± 2m Dec 28°6' ± 12' has a luminosity Lx = 2.6 x 1044 ergs/s. As the source is extended, with a size of about 45', this argues against the possibility that a single galaxy is responsible for the emission.
In sunrise/sunset tables, the atmospheric refraction is assumed to be 34 arcminutes, and the assumed semidiameter (apparent radius) of the Sun is 16 arcminutes. (The apparent radius varies slightly depending on time of year, slightly larger at perihelion in January than aphelion in July, but the difference is comparatively small.) Their combination means that when the upper limb of the Sun is on the visible horizon, its centre is 50 arcminutes below the geometric horizon, which is the intersection with the celestial sphere of a horizontal plane through the eye of the observer. These effects make the day about 14 minutes longer than the night at the equator and longer still towards the poles. The real equality of day and night only happens in places far enough from the equator to have a seasonal difference in day length of at least 7 minutes, actually occurring a few days towards the winter side of each equinox.
Celestial globe with clockwork; 1579; partly gilded silver, gilded brass and steel; overall: 27.3 × 20.3 × 19.1 cm, diameter of the globe: 14 cm; from Vienna; Metropolitan Museum of Art (New York City) Celestial globe; after 1621; paper, brass, oak and stained and light-colored wood; overall: 52.1 × 47.3 cm, diameter of the globe: 34 cm; from Amsterdam; Metropolitan Museum of Art Celestial globes show the apparent positions of the stars in the sky. They omit the Sun, Moon, and planets because the positions of these bodies vary relative to those of the stars, but the ecliptic, along which the Sun moves, is indicated. There is an issue regarding the “handedness” of celestial globes. If the globe is constructed so that the stars are in the positions they actually occupy on the imaginary celestial sphere, then the star field will appear reversed on the surface of the globe (all the constellations will appear as their mirror images).
Right ascension (blue) and declination (green) as seen from outside the celestial sphere Various hour angles are depicted here. The symbol ♈ is the vernal equinox direction. Assuming the day of the year is the March equinox: the Sun lies toward the grey arrow, the star marked by a green arrow will appear to rise somewhere in the east about midnight (the Earth drawn from "above" turns anticlockwise). After the observer reaches the green arrow dawn comes over-powering (see blue sky Rayleigh scattering) the star's light about six hours before it sets on the western horizon. The Right ascension of the star is about 18h. 18h means it is a March early-hours star and in blue sky in the morning. If 12h RA, the star would be a March all-night star as opposite the March equinox. If 6h RA the star would be a March late-hours star, at its high (meridian) at dusk.
He starts from the following three premises: # Nothing creates itself, since the act of creating necessitates its existence (see also Saadia, "Emunot," i. 2) # the causes of things are necessarily limited in number, and lead to the presumption of a first cause which is necessarily self-existent, having neither beginning nor end, because everything that has an end must have a beginning # all composite beings have a beginning; and a cause must necessarily be created. The world is beautifully arranged and furnished like a great house, of which the sky forms the ceiling, the earth the floor, the stars the lamps, and man is the proprietor, to whom the three kingdoms—the animal, the vegetable, and the mineral—are submitted for use, each of these being composed of the four elements. Nor does the celestial sphere, composed of a fifth element—"Quinta Essentia", according to Aristotle, and of fire, according to others—make an exception.
Herodotus wrote that the Greeks learnt the practice of dividing the day into 12 parts, about the polos, and the gnomon from the Babylonians. (The exact meaning of his use of the word polos is unknown, current theories include: "the heavenly dome", "the tip of the axis of the celestial sphere", or a spherical concave sundial.) Yet even Herodotus' claims on Babylonian influence are contested by some modern historians, such as L. Zhmud, who points out that the division of the day into twelve parts (and by analogy the year) was known to the Egyptians already in the second millennium, the gnomon was known to both Egyptians and Babylonians, and the idea of the "heavenly sphere" was not used outside of Greece at this time. Less controversial than the position that Thales learnt Babylonian mathematics is the claim he was influenced by Egyptians. Pointedly historian S. N. Bychkov holds that the idea that the base angles of an isosceles triangle are equal likely came from Egypt.
The Explorer 11 telescope, developed at MIT under the direction of William L. Kraushaar, used a combination of a sandwich scintillator detector along with a Cherenkov counter to measure the arrival directions and energies of high-energy gamma rays. Since the telescope could not be aimed, the spacecraft was set in a slow spin to scan the celestial sphere. Due to a higher than planned orbit that carried the spacecraft into the detector-jamming radiation of the Van Allen belt, and an early failure of the on-board tape recorder, only 141 hours of useful observing time could be culled from about 7 months during which the instrument operated. During this time thirty-one "gamma-ray signature" events were recorded when the telescope was pointing in directions well away from the Earth's atmosphere, which is a relatively bright source of gamma rays produced in interactions of ordinary cosmic ray protons with air atoms.
Monument and effigies, in Salisbury Cathedral, Wiltshire, of Sir Thomas Gorges (1536-1610) and his wife Helena Snakenborg (d.1635) He was buried in Salisbury Cathedral, Wiltshire, where survives (at the east end of the north choir aisle, on the north side of the Lady Chapel) his magnificent monument with recumbent effigies of himself and his wife erected in 1635 by his son Edward Gorges, 1st Baron Gorges,Per Latin inscription after the death of his widow. The sides of the elaborate canopy above the effigies, supported on four Solomonic columns, display sculpted framework polyhedra, including two cuboctahedra and an icosahedron and the canopy is topped by a celestial globe surmounted by a dodecahedron. These devices are possibly a reference to Leonardo da Vinci's drawings for Luca Pacioli (Divina Proportione, Paganini, Venice, 1509),Mathematical Gazetteer of the British Isles ultimately based on Plato's Timaeus in which each of the regular polyhedra (or Five Regular Solids) are assigned to the atomic structure of one of the Five Elements, with the dodecahedron representing the whole Celestial Sphere.
The adoption of European astronomy, facilitated by the failure of indigenous astronomy to make progress, was accompanied by a sinocentric reinterpretation that declared the imported ideas Chinese in origin: > European astronomy was so much judged worth consideration that numerous > Chinese authors developed the idea that the Chinese of antiquity had > anticipated most of the novelties presented by the missionaries as European > discoveries, for example, the rotundity of the Earth and the "heavenly > spherical star carrier model." Making skillful use of philology, these > authors cleverly reinterpreted the greatest technical and literary works of > Chinese antiquity. From this sprang a new science wholly dedicated to the > demonstration of the Chinese origin of astronomy and more generally of all > European science and technology. Although mainstream Chinese science until the 17th century held the view that the Earth was flat, square, and enveloped by the celestial sphere, this idea was criticized by the Jin-dynasty scholar Yu Xi (fl. 307–345), who suggested that the Earth could be either square or round, in accordance with the shape of the heavens.
Wright was a skilled designer of mathematical instruments. According to the 1615 Caius annals, "[h]e was excellent both in contrivance and execution, nor was he inferior to the most ingenious mechanic in the making of instruments, either of brass or any other matter". For Prince Henry, he made models of an astrolabe and a pantograph, and created or arranged to be created out of wood a form of armillary sphere which replicated the motions of the celestial sphere, the circular motions of the sun and moon, and the places and possibilities of them eclipsing each other. The sphere was designed for a motion of 17,100 years, if the machine should last that long. In 1613 Wright published The Description and Use of the Sphære, which described the use of this device. The sphere was lost during the English Civil War, but found in 1646 in the Tower of London by the mathematician and surveyor Sir Jonas Moore, who was later appointed Surveyor General of the Ordnance Office and became a patron and the principal driving force behind the establishment of the Royal Observatory at Greenwich.
The model flat geometry for the ambient construction is the future null cone in Minkowski space, with the origin deleted. The celestial sphere at infinity is the conformal manifold M, and the null rays in the cone determine a line bundle over M. Moreover, the null cone carries a metric which degenerates in the direction of the generators of the cone. The ambient construction in this flat model space then asks: if one is provided with such a line bundle, along with its degenerate metric, to what extent is it possible to extend the metric off the null cone in a canonical way, thus recovering the ambient Minkowski space? In formal terms, the degenerate metric supplies a Dirichlet boundary condition for the extension problem and, as it happens, the natural condition is for the extended metric to be Ricci flat (because of the normalization of the normal conformal connection.) The ambient construction generalizes this to the case when M is conformally curved, first by constructing a natural null line bundle N with a degenerate metric, and then solving the associated Dirichlet problem on N × (-1,1).
Much more precise spacecraft measurements of the microwave background from WMAP in 2003–2010 and Planck in 2013–2015 have continued to support the model and pin down the parameter values, most of which are now constrained below 1 percent uncertainty. There is currently active research into many aspects of the ΛCDM model, both to refine the parameters and possibly detect deviations. In addition, ΛCDM has no explicit physical theory for the origin or physical nature of dark matter or dark energy; the nearly scale-invariant spectrum of the CMB perturbations, and their image across the celestial sphere, are believed to result from very small thermal and acoustic irregularities at the point of recombination. A large majority of astronomers and astrophysicists support the ΛCDM model or close relatives of it, but Milgrom, McGaugh, and Kroupa are leading critics, attacking the dark matter portions of the theory from the perspective of galaxy formation models and supporting the alternative modified Newtonian dynamics (MOND) theory, which requires a modification of the Einstein field equations and the Friedmann equations as seen in proposals such as modified gravity theory (MOG theory) or tensor–vector–scalar gravity theory (TeVeS theory).
Boötes is in a part of the celestial sphere facing away from the plane of our home Milky Way galaxy, and so does not have open clusters or nebulae. Instead, it has one bright globular cluster and many faint galaxies. The globular cluster NGC 5466 has an overall magnitude of 9.1 and a diameter of 11 arcminutes. It is a very loose globular cluster with fairly few stars and may appear as a rich, concentrated open cluster in a telescope. NGC 5466 is classified as a Shapley-Sawyer Concentration Class 12 cluster, reflecting its sparsity. Its fairly large diameter means that it has a low surface brightness, so it appears far dimmer than the catalogued magnitude of 9.1 and requires a large amateur telescope to view. Only approximately 12 stars are resolved by an amateur instrument. Boötes has two bright galaxies. NGC 5248 (Caldwell 45) is a type Sc galaxy (a variety of spiral galaxy) of magnitude 10.2. It measures 6.5 by 4.9 arcminutes. Fifty million light-years from Earth, NGC 5248 is a member of the Virgo Cluster of galaxies; it has dim outer arms and obvious H II regions, dust lanes, and young star clusters. NGC 5676 is another type Sc galaxy of magnitude 10.9.

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