1.
Chad Trujillo
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Chadwick A. Chad Trujillo is an American astronomer, discoverer of minor planets and the co-discoverer of Eris, the most massive dwarf planet known in the Solar System. Trujillo works with software and has examined the orbits of the numerous trans-Neptunian objects. In late August 2005, it was announced that Trujillo, along with Michael E. Brown, as a result of the discovery of the satellite Dysnomia, Eris was the first TNO known to be more massive than Pluto. Trujillo attended Oak Park and River Forest High School in Oak Park, Trujillo was later a postdoctoral scholar at Caltech, and is currently an astronomer at the Gemini Observatory in Hawaii. He studies the Kuiper belt and the outer Solar System, the main-belt asteroid 12101 Trujillo is named for him. Trujillo is credited by the Minor Planet Center with the discovery and co-discovery of 50 numbered minor planets between 1996 and 2007, including many trans-Neptunian objects from the Kuiper belt, makemake, co-discovered with Brown and Rabinowitz in 2005, one of the first 5 official dwarf planets
2.
David C. Jewitt
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Jewitt is an English astronomer and professor of astronomy at UCLAs Earth, Planetary, and Space Science Department in California. He is best known for having discovered the first body in the Kuiper belt and he was born in 1958 in England, and is a 1979 graduate of University College, London. Jewitt received an M. Sc. and a Ph. D. in astronomy at the California Institute of Technology in 1980 and 1983, respectively. His research interests cover all aspects of the system, including the trans-Neptunian Solar System, Solar System formation, ice in the asteroids. Along with Jane Luu, he discovered the first Kuiper belt object in 1992 and those resonant objects in the 3,2 mean-motion resonance he called plutinos as a reminder that Pluto is one such object. Jewitt is a member of national academies. He was also awarded the Kavli Prize in the same year and he is a fellow of the Norwegian Academy of Science and Letters. Jewitt is also featured in the 1985 BBC Horizon episode Halleys Comet, The Apparition and he has also discovered the Jovian moon Adrastea on images taken by Voyager 2 in 1979, and is credited by the Minor Planet Center with the discovery of more than 40 minor planets. The inner main-belt asteroid 6434 Jewitt, discovered by Edward Bowell in 1981, was named in his honor, naming citation was published on 1 July 1996. A selection of his recent publications includes, J. Li, D. Jewitt, J. Clover, outburst of Comet 17P/Holmes Observed With The Solar Mass Ejection Imager. A Near-Infrared Search for Silicates in Jovian Trojan Asteroids, M. Drahus, D. Jewitt, A. Guilbert-Lepoutre, W. Waniak, J. Hoge, D. Lis, H. Yoshida and R. Peng. Rotation State of Comet 103P/Hartley 2 from Radio Spectroscopy at 1-mm, D. Jewitt, H. Weaver, M. Mutchler, S. Larson and J. Agarwal. Hubble Space Telescope Observations of Main Belt Comet Scheila,733, L4 H. Hsieh, P. Lacerda, M. Ishiguro and D. Jewitt. Physical Properties of Main-Belt Comet 176P/LINEAR, D. Jewitt, S. Stuart and J. Li. Prediscovery Observations of Disrupting Asteroid P/2010 A2, thermal Shadows and Compositional Structure in Comet Nuclei. Ap. J.743,31 D. Jewitt and A. Guilbert-Lepoutre, limits to Ice on Asteroids Themis and Cybele. J.143,21 Curriculum vitae Publications David Jewitt website Video interview on YouTube about the Kuiper belt, Pan-STARRS, and icy main-belt comets
3.
Minor planet
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A minor planet is an astronomical object in direct orbit around the Sun that is neither a planet nor exclusively classified as a comet. Minor planets can be dwarf planets, asteroids, trojans, centaurs, Kuiper belt objects, as of 2016, the orbits of 709,706 minor planets were archived at the Minor Planet Center,469,275 of which had received permanent numbers. The first minor planet to be discovered was Ceres in 1801, the term minor planet has been used since the 19th century to describe these objects. The term planetoid has also used, especially for larger objects such as those the International Astronomical Union has called dwarf planets since 2006. Historically, the asteroid, minor planet, and planetoid have been more or less synonymous. This terminology has become complicated by the discovery of numerous minor planets beyond the orbit of Jupiter. A Minor planet seen releasing gas may be classified as a comet. Before 2006, the IAU had officially used the term minor planet, during its 2006 meeting, the IAU reclassified minor planets and comets into dwarf planets and small Solar System bodies. Objects are called dwarf planets if their self-gravity is sufficient to achieve hydrostatic equilibrium, all other minor planets and comets are called small Solar System bodies. The IAU stated that the minor planet may still be used. However, for purposes of numbering and naming, the distinction between minor planet and comet is still used. Hundreds of thousands of planets have been discovered within the Solar System. The Minor Planet Center has documented over 167 million observations and 729,626 minor planets, of these,20,570 have official names. As of March 2017, the lowest-numbered unnamed minor planet is 1974 FV1, as of March 2017, the highest-numbered named minor planet is 458063 Gustavomuler. There are various broad minor-planet populations, Asteroids, traditionally, most have been bodies in the inner Solar System. Near-Earth asteroids, those whose orbits take them inside the orbit of Mars. Further subclassification of these, based on distance, is used, Apohele asteroids orbit inside of Earths perihelion distance. Aten asteroids, those that have semi-major axes of less than Earths, Apollo asteroids are those asteroids with a semimajor axis greater than Earths, while having a perihelion distance of 1.017 AU or less. Like Aten asteroids, Apollo asteroids are Earth-crossers, amor asteroids are those near-Earth asteroids that approach the orbit of Earth from beyond, but do not cross it
4.
Trans-Neptunian object
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A trans-Neptunian object is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune,30 astronomical units. Twelve minor planets with a semi-major axis greater than 150 AU and perihelion greater than 30 AU are known, the first trans-Neptunian object to be discovered was Pluto in 1930. It took until 1992 to discover a second trans-Neptunian object orbiting the Sun directly,1992 QB1, as of February 2017 over 2,300 trans-Neptunian objects appear on the Minor Planet Centers List of Transneptunian Objects. Of these TNOs,2,000 have a perihelion farther out than Neptune, as of November 2016,242 of these have their orbits well-enough determined that they have been given a permanent minor planet designation. The largest known object is Pluto, followed by Eris,2007 OR10, Makemake. The Kuiper belt, scattered disk, and Oort cloud are three divisions of this volume of space, though treatments vary and a few objects such as Sedna do not fit easily into any division. The orbit of each of the planets is slightly affected by the influences of the other planets. Discrepancies in the early 1900s between the observed and expected orbits of Uranus and Neptune suggested that there were one or more additional planets beyond Neptune, the search for these led to the discovery of Pluto in February 1930, which was too small to explain the discrepancies. Revised estimates of Neptunes mass from the Voyager 2 flyby in 1989 showed that the problem was spurious, Pluto was easiest to find because it has the highest apparent magnitude of all known trans-Neptunian objects. It also has an inclination to the ecliptic than most other large TNOs. After Plutos discovery, American astronomer Clyde Tombaugh continued searching for years for similar objects. For a long time, no one searched for other TNOs as it was believed that Pluto. Only after the 1992 discovery of a second TNO,1992 QB1, a broad strip of the sky around the ecliptic was photographed and digitally evaluated for slowly moving objects. Hundreds of TNOs were found, with diameters in the range of 50 to 2,500 kilometers, Pluto and Eris were eventually classified as dwarf planets by the International Astronomical Union. Kuiper belt objects are classified into the following two groups, Resonant objects are locked in an orbital resonance with Neptune. Objects with a 1,2 resonance are called twotinos, and objects with a 2,3 resonance are called plutinos, after their most prominent member, classical Kuiper belt objects have no such resonance, moving on almost circular orbits, unperturbed by Neptune. Examples are 1992 QB1,50000 Quaoar and Makemake, the scattered disc contains objects farther from the Sun, usually with very irregular orbits. A typical example is the most massive known TNO, Eris, scattered-extended —Scattered-extended objects have a Tisserand parameter greater than 3 and have a time-averaged eccentricity greater than 0
5.
Plutino
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In astronomy, a plutino is a trans-Neptunian object in 2,3 mean-motion resonance with Neptune. For every 2 orbits that a plutino makes, Neptune orbits 3 times, the term plutino derived from the dwarf planet Pluto, the largest and the first plutino discovered. The term does not imply common physical characteristics, Plutinos are named after mythological creatures associated with the underworld. Plutinos form the part of the Kuiper belt and represent about a quarter of the known Kuiper belt objects. Plutinos are the largest class of the resonant trans-Neptunian objects, aside from Pluto itself, the first plutino,1993 RO, was discovered on September 16,1993. It is thought that objects that are currently in mean orbital resonances with Neptune initially followed independent heliocentric paths. As Neptune migrated outward early in the Solar Systems history, the bodies it approached would have been scattered, during this process, the 3,2 resonance is the strongest and most stable among all resonances. This is the reason it contains the largest number of bodies. The orbital periods of plutinos cluster around 247.3 years, the gravitational influence of Pluto is usually neglected given its small mass. However, the width is very narrow and only a few times larger than Pluto’s Hill sphere. Consequently, depending on the eccentricity, some plutinos will be driven out of the resonance by interactions with Pluto. Numerical simulations suggest that the orbits of plutinos with an eccentricity 10%–30% smaller or larger than that of Pluto are not stable over Ga timescales, the plutinos brighter than HV=6 include, David Jewitt on Plutinos Minor Planet Center, List of TNOs MPC List of Distant Minor Planets
. Bibcode:2012A&A...541A..93M. doi:10.1051/0004-6361/201118562.
