Tell Me This New Planetary Object Isn't A DoughnutPlanets sort of look like big basketballs in space, floating around aimlessly.
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When spacecraft leave the Earth they are destined to either land somewhere, orbit something, or fly by a planetary object.
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But searching for a tenth planetary object as small as this one in a region as vast as the Kuiper belt may not yield any definitive answers soon.
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This planetary object is reported to be about half the mass but slightly larger than the planet Jupiter at 0.467(+0.047, -0.024) M_Jup.
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Planetary object being vaporized by its parent star (artist concept) The supposed planetesimal, ZTF J0139+5245 b, is presumably being ripped apart by the star.
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Patryk Lykawka of Kobe University claimed that the gravitational attraction of an unseen large planetary object, perhaps the size of Earth or Mars, might be responsible.
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According to Marcy & Benitz (1989) detected a possible periodicity of 416 days, inferring possible presence of a massive planetary object with minimum mass of 11 times that of Jupiter. So far the planet has not been confirmed.
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The minor planet is notable because it is the first observed planetary object to transit a white dwarf, providing clues of its possible interactions when its parent star reached the end of its lifetime as a red giant.
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This planetary object is reported to be about 3.3 times the mass of the planet Jupiter and 1.17 times its size with an orbital period of 8.88 days. It is a hot Jupiter with a temperature between 700 and 1000 °C.
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Radial velocity variations with a period of 142 days hint about the possible presence of a planetary companion orbiting Beta Ophiuchi. Thus far, no planetary object has been confirmed; while periodic radial pulsations caused by intrinsic stellar variability could explain the observed variations.
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According to Marcy & Benitz (1989) detected a possible periodicity of 510 days, inferring possible presence of a massive planetary object with minimum mass of 12 times that of Jupiter in highly eccentric orbit (e=0.6). So far the planet has not been confirmed.
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"Tell Me a Story." (Includes podcast). Radiolab.org. Accessed May 2012. Astrobiologist David Morrison has spoken of repeated disruption of his work by popular anti-scientific phenomena, having been called upon to assuage public fears of an impending cataclysm involving an unseen planetary object—first in 2008, and again in 2012 and 2017.
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Much of what is known is from the use of techniques such as astronomical spectroscopy and sample return. Lander spacecraft have explored the surfaces of planets Mars and Venus. Mars is the only other planet to have had its surface explored by a mobile surface probe (rover). Titan is the only non-planetary object of planetary mass to have been explored by lander.
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In 1943 he claimed to have discovered (with Erik Holberg) a planetary companion of the star system 70 Ophiuchi and other stars. He claimed that this planetary object had 10 times the mass of the planet Jupiter and a 17-year orbital period. This caused quite a sensation at the time. A critical analysis by Wulff Heintz later discredited these claims.
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In 2008 Grinin et al. invoke the possible presence of a substellar object to explain peculiar and periodic eclipses occurring to the young star every 4.7 years. The presence of a planetary object is still invoked in a recent research. They infer a maximum mass of 6 times that of Jupiter for the perturbing object and an orbital separation of 3.3 astronomical units.
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The planetary object orbits a (DB-type) white dwarf. It has ended its main sequence lifetime and will continue to cool for billions of years to come in the future. Based on recent studies and its mass, the star was likely an early F-type main sequence star (spectral type F0) before it became a red giant. The star has a mass of 0.6 and a radius of 0.02 (1.4 ).
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The supposed planetesimal, WD 1145+017 b, with a 4.5 hour orbit, is being ripped apart by the star and is a remnant of the former planetary system that the star hosted before becoming a white dwarf. It is the first observation of a planetary object being shredded by a white dwarf. Several other large pieces have been seen in orbit as well. All the various larger pieces have orbits of 4.5 to 4.9 hours.
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Radial velocity variations of Theta Cygni have been detected by the ELODIE team while searching of extrasolar planets. Desort et al. (2009) infer these variations are not caused by a dim stellar companion roughly 80 Astronomical Units away from the star, but suggest instead the presence of a perturbing planetary object, twice as massive as Jupiter and orbiting around the primary star in roughly 150 days. This extrasolar planet has yet to be confirmed.
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It is possible that subsurface habitats could be insulated from such changes and that extremophiles on or near the surface might survive through adaptions such as hibernation (cryptobiosis) and/or hyperthermostability. Tardigrades, for example, can survive in a dehydrated state temperatures between and . Life on a planetary object orbiting outside CHZ might hibernate on the cold side as the planet approaches the apastron where the planet is coolest and become active on approach to the periastron when the planet is sufficiently warm.
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Greenhill et al. (2009) would invoke the presence of a third object to explain orbital period variations with an apparent periodicity of roughly 35 years. The third body could yield a minimum mass 7 times greater than Jupiter and be located 9.5 Astronomical Units away from the cataclysmic variable system, being likely either a massive planetary object or else a very low-mass brown dwarf. It is likely that the apparent change is due to solar-cycle type magnetic activity in the secondary star.
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Artistic rendering of R Leonis's putative evaporating planetary companion In 2009 Wiesemeyer et al. proposed that quasi-periodic fluctuations observed for the star R Leonis may be due to the presence of an evaporating substellar companion, probably an extrasolar planet. They have inferred a putative mass for the orbiting body of twice the mass of Jupiter, orbital period of 5.2 years and likely orbital separation of 2.7 astronomical units. If confirmed such a planetary object could likely be an evaporating planet, with long comet-like trail as hinted by intense SiO maser emissions.
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NOEMA has observed the most distant galaxy known to date. Together with the IRAM 30-meter telescope it made the first complete and detailed radio images of nearby galaxies and their gas. NOEMA also obtained the first image of a gas disk surrounding a double star system (Guilloteau et al. 1994). Its antennas captured for the first time a cavity in one of these disks, a major hint for the existence of a planetary object orbiting the new star and absorbing matter on its trajectory (GG tau, Piétu et al. 2011).
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Evidence for a planetary system was discovered in 1998 by the observation of asymmetries in this dust ring. The clumping in the dust distribution could be explained by gravitational interactions with a planet orbiting just inside the dust ring. In 1987, the detection of an orbiting planetary object was announced by Bruce Campbell, Gordon Walker and Stephenson Yang. From 1980 to 2000, a team of astronomers led by Artie P. Hatzes made radial velocity observations of Epsilon Eridani, measuring the Doppler shift of the star along the line of sight.
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A helium-rich planetary object may also form from a low-mass white dwarf, which gets depleted of hydrogen via mass transfer in a close binary system with a second, massive object like a neutron star. One scenario involves an AM CVn type of symbiotic binary star composed of two helium-core white dwarfs surrounded by a circumbinary helium accretion disk formed during mass transfer from the less massive to the more massive white dwarf. After it loses most of its mass, the less massive white dwarf may approach planetary mass.
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Although a periodicity of 73.26 days has been observed in the star's radial velocity, it seems likely to be bound more to stellar activity than to a planetary object in close orbit. No substellar companion has been detected so far around Pi³ Orionis and the McDonald Observatory team has set limits to the presence of one or more planets with masses between 0.84 and 46.7 Jupiter masses and average separations spanning between 0.05 and 5.2 astronomical units. Thus, so far it appears that planets could easily orbit in the habitable zone without any complications caused by a gravitationally perturbing body.
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For many years after Apollo, the binary accretion model was settled on as the best hypothesis for explaining the Moon's origins, even though it was known to be flawed. Then, at a conference in Kona, Hawaii in 1984, a compromise model was composed that accounted for all of the observed discrepancies. Originally formulated by two independent research groups in 1976, the giant impact model supposed that a massive planetary object, the size of Mars, had collided with Earth early in its history. The impact would have melted Earth's crust, and the other planet's heavy core would have sunk inward and merged with Earth's.
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This is a list of named craters on Callisto, one of the many moons of Jupiter, the most heavily cratered natural satellite in the Solar System (for other features, see list of geological features on Callisto). As of 2017, the Working Group for Planetary System Nomenclature has officially named a total of 141 craters on Callisto, more than on any other non-planetary object such as Ganymede (131), Rhea (128), Vesta (90), Ceres (90), Dione (73), Iapetus (58), Enceladus (53), Tethys (50) and Europa (41). Although some Callistoan craters refer to the nymph Callisto from Greek mythology, they are officially named after characters from myths and folktales of cultures of the Far North. .
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The Nibiru cataclysm is a supposed disastrous encounter between the Earth and a large planetary object (either a collision or a near-miss) that certain groups believed would take place in the early 21st century. Believers in this doomsday event usually refer to this object as Nibiru or Planet X. The idea was first put forward in 1995 by Nancy Lieder, founder of the website ZetaTalk. Lieder describes herself as a contactee with the ability to receive messages from extraterrestrials from the Zeta Reticuli star system through an implant in her brain. She states that she was chosen to warn mankind that the object would sweep through the inner Solar System in May 2003 (though that date was later postponed) causing Earth to undergo a physical pole shift that would destroy most of humanity.
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Red dwarfs that have masses less than 20% of that of the Sun cannot have habitable moons around giant planets, as the small size of the circumstellar habitable zone would put a habitable moon so close to the star that it would be stripped from its host planet. In such a system, a moon close enough to its host planet to maintain its orbit would have tidal heating so intense as to eliminate any prospects of habitability. Artist's concept of a planet on an eccentric orbit that passes through the CHZ for only part of its orbit A planetary object that orbits a star with high orbital eccentricity may spend only some of its year in the CHZ and experience a large variation in temperature and atmospheric pressure. This would result in dramatic seasonal phase shifts where liquid water may exist only intermittently.
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Since no certain planetary object has been detected around either star so far, McDonald Observatory team has set limits to the presence of one or more planets around 61 Cygni A and 61 Cygni B with masses between 0.07 and 2.1 Jupiter masses and average separations spanning between 0.05 and 5.2 AU. Because of the proximity of this system to the Sun, it is a frequent target of interest for astronomers. Both stars were selected by NASA as "Tier 1" targets for the proposed optical Space Interferometry Mission. This mission is potentially capable of detecting planets with as little as 3 times the mass of the Earth at an orbital distance of 2 AU from the star. Measurements of this system appeared to have detected an excess of far infrared radiation, beyond what is emitted by the stars.
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Raj is an astrophysicist in the Physics Department at Caltech, best known for a publication on Kuiper belt object size distribution. For his discovery of a planetary object beyond the Kuiper belt, , which he named "Planet Bollywood", Raj was included in People magazine's "30 (Visionaries) Under 30 (Years of Age) to Watch", received a larger office, and became a celebrity of sorts, drawing the envy of his friends. After six months of failed research on the composition of trans- Neptunian objects, Raj feared being deported back to India (at which point, he describes spending his time at work as "mostly checking e-mail, updating his Facebook status, and messing up Wikipedia entries"). To stay in the country, he sought out a research position in stellar evolution with Professor Laughlin; the job proposition failed as the research team included an attractive woman, and Raj, who became drunk so he could talk to her, made an inappropriate comment.
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The planetary object was discovered by the Kepler spacecraft on its secondary mission, K2: Second Light, an extension of its original mission from 2009 to 2013. Observations were taken over a period of about a month starting from April 2015 using the 1.2-meter telescope at the Fred L. Whipple Observatory along with another telescope located in Chile. The white dwarf star was not originally targeted as part of the mission, however data revealed that there was dips in this star's light curve, and as such investigations were made to figure out what causing the dips, just like the same procedure that was used on the stars that were targeted by the K2 mission. Two transits were detected on 11 April over a period of 4 hours apart, and again on 17 April, however this one was 180° out of phase (inclination probably) from the 11 April transits. The spectra of WD 1145+047 was studied and it revealed that the star contained magnesium, aluminum, silicon, calcium, iron, and nickel.
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