The Jupiter trojans, commonly called trojan asteroids or simply trojans, are a large group of asteroids that share the planet Jupiter's orbit around the Sun. Relative to Jupiter, each trojan librates around one of Jupiter's stable Lagrange points: either L4, existing 60° ahead of the planet in its orbit, or L5, 60° behind. Jupiter trojans are distributed in two elongated, curved regions around these Lagrangian points with an average semi-major axis of about 5.2 AU.
In planetary astronomy, a centaur is a small Solar System body that orbits the Sun between Jupiter and Neptune and crosses the orbits of one or more of the giant planets. Centaurs generally have unstable orbits because they cross or have crossed the orbits of the giant planets; almost all their orbits have dynamic lifetimes of only a few million years, but there is one known centaur, 514107 Kaʻepaokaʻawela, which may be in a stable orbit. Centaurs typically exhibit the characteristics of both asteroids and comets. They are named after the mythological centaurs that were a mixture of horse and human. Observational bias toward large objects makes determination of the total centaur population difficult. Estimates for the number of centaurs in the Solar System more than 1 km in diameter range from as low as 44,000 to more than 10,000,000.
In astronomy, a resonant trans-Neptunian object is a trans-Neptunian object (TNO) in mean-motion orbital resonance with Neptune. The orbital periods of the resonant objects are in a simple integer relations with the period of Neptune, e.g. 1:2, 2:3, etc. Resonant TNOs can be either part of the main Kuiper belt population, or the more distant scattered disc population.
Neptune trojans are bodies that orbit the Sun near one of the stable Lagrangian points of Neptune, similar to the trojans of other planets. They therefore have approximately the same orbital period as Neptune and follow roughly the same orbital path. Thirty-one Neptune trojans are currently known, of which 27 orbit near the Sun–Neptune L4 Lagrangian point 60° ahead of Neptune and four orbit near Neptune's L5 region 60° behind Neptune. The Neptune trojans are termed 'trojans' by analogy with the Jupiter trojans.
The Panoramic Survey Telescope and Rapid Response System located at Haleakala Observatory, Hawaii, US, consists of astronomical cameras, telescopes and a computing facility that is surveying the sky for moving or variable objects on a continual basis, and also producing accurate astrometry and photometry of already-detected objects. In January 2019 the second Pan-STARRS data release was announced. At 1.6 petabytes, it is the largest volume of astronomical data ever released.
In astronomy, a trojan is a small celestial body (mostly asteroids) that shares the orbit of a larger body, remaining in a stable orbit approximately 60° ahead of or behind the main body near one of its Lagrangian points L4 and L5. Trojans can share the orbits of planets or of large moons.
In astronomy, a co-orbital configuration is a configuration of two or more astronomical objects orbiting at the same, or very similar, distance from their primary; i.e., they are in a 1:1 mean-motion resonance..
83982 Crantor (provisional designation 2002 GO9) is a centaur in a 1:1 resonance with Uranus, approximately 60 kilometers (37 miles) in diameter. It was discovered on 12 April 2002, by astronomers of the Near-Earth Asteroid Tracking at the Palomar Observatory in California, United States. This minor planet was named for Crantor from Greek mythology.
(445473) 2010 VZ98 (provisional designation 2010 VZ98) is a trans-Neptunian object of the scattered disc, orbiting the Sun in the outermost region of the Solar System. It has a diameter of approximately 400 kilometers.
(148975) 2001 XA255, provisional designation: 2001 XA255, is a dark minor planet in the outer Solar System, classified as centaur, approximately 38 kilometers (24 miles) in diameter. It was discovered on 9 December 2001, by David C. Jewitt, Scott S. Sheppard, and Jan Kleyna observing from the Mauna Kea Observatory. The object is currently trapped in a 1:1 mean-motion resonance with Neptune following a path of the horseshoe type.
(316179) 2010 EN65 is a trans-Neptunian object orbiting the Sun. However, with a semi-major axis of 30.8 AU, the object is actually a jumping Neptune trojan, co-orbital with Neptune, as the giant planet has a similar semi-major axis of 30.1 AU. The body is jumping from the Lagrangian point L4 into L5 via L3. As of 2016, it is 54 AU from Neptune. By 2070, it will be 69 AU from Neptune.
2010 EU65 is a centaur, approximately 64 kilometers (40 miles) in diameter, orbiting the Sun in the outer Solar System. The object is also a promising Uranus horseshoe librator candidate. It was first observed on 13 March 2010, by American astronomers David Rabinowitz and Suzanne Tourtellotte, observing from Cerro Tololo and La Silla Observatory in Chile. As of 2021, it has neither been numbered nor named.
2011 SC191 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).
(687170) 2011 QF99 is a minor planet from the outer Solar System and the first known Uranus trojan to be discovered. It measures approximately 60 kilometers (37 miles) in diameter, assuming an albedo of 0.05. It was first observed 29 August 2011 during a deep survey of trans-Neptunian objects conducted with the Canada–France–Hawaii Telescope, but its identification as Uranian trojan was not announced until 2013.
2012 FC71, also written 2012 FC71, is a small asteroid trapped in a Kozai resonance with the Earth.
2013 ND15 (also written 2013 ND15) is an asteroid that is a temporary trojan of Venus, the first known Venus trojan.
(472651) 2015 DB216 is a centaur and Uranus co-orbital discovered on February 27, 2015, by the Mount Lemmon Survey. It is the second known centaur on a horseshoe orbit with Uranus, and the third Uranus co-orbital discovered after 2011 QF99 (a Trojan) and 83982 Crantor (a horseshoe librator). A second Uranian Trojan, 2014 YX49, was announced in 2017.
P/2019 LD2 (ATLAS) is a Jupiter-family comet discovered by the Asteroid Terrestrial-impact Last Alert System on 10 June 2019. It was initially reported as the first known Jupiter trojan asteroid to display cometary activity, but its classification as a Jupiter trojan was retracted after closer examination and a longer observation arc revealed its orbit to be unstable like a typical Jupiter family comet and implied that its position near the trojans is temporary.
A Uranus trojan is an asteroid that shares an orbit with Uranus and the Sun. Predicted in simulations earlier, two trojans have been discovered in Uranus’s Lagrangian point L4 (leading Uranus).
