10199 Chariklo

10199 Chariklo or Chariklo for short is the largest centaur (small solar system body). Currently, it is the only centaur or asteroid to possess a ring
system. The body orbits the sun between Uranus and Saturn, having an orbital period of 62.93 years. On 26 March 2014, astronomers announced the discovery of two rings (nicknamed Oiapoque and Chuí after the rivers that define Brazil's borders) around Chariklo by observing a stellar occultation, making it the first minor planet known to have rings.
==Discovery and Naming==
Chariklo was discovered on February 15, 1997, by Spacewatch member James V. Scotti. Chariklo is named after the nymph Chariclo (Χαρικλώ), the wife of Chiron and the daughter of Apollo.
== Orbit==
Centaurs originated from the Kuiper Belt and are naturally in unstable orbits due to them being between large planets. This will usually lead to ejection from the Solar System, an impact with a planet or The Sun, or transition into a short-period comet. Chariklo lies within 0.09 AU of the 4:3 resonance of Uranus and is estimated to have a relatively long orbital half-life of about 10.3 Myr. Orbital simulations of twenty clones of Chariklo suggest that Chariklo will not start to regularly come within 3 AU (450 Gm) of Uranus for about thirty thousand years.
During the perihelic oppositions of 2003–04, Chariklo had an apparent magnitude of +17.7. As of 2014, Chariklo was 14.8 AU from the Sun.
==Physical Characteristics==
A stellar occultation in 2013 revealed that Chariklo has two rings with radii 386 and 400 km and widths of about 6.9 km and 0.12 km respectively. The rings are approximately 14 km apart. This makes Chariklo the smallest known object to have rings. The existence of a ring system around a minor planet was unexpected because it had been thought that rings could only be stable around much more massive bodies. Ring systems around minor bodies had not previously been discovered despite the search for them through direct imaging and stellar occultation techniques. Chariklo's rings should disperse over a period of at most a few million years, so either they are very young, or they are actively contained by shepherd moons with a mass comparable to that of the rings. However, other research suggests that Chariklo's elongated shape combined with its fast rotation can clear material in an equatorial disk through Lindblad resonances and explain the survival and location of the rings, a mechanism valid also for the ring of Haumea.
It is speculated the the other centaur 2060 Chiron may have a similar pair of rings.
Category:Dwarf Planet Candidate
Category:Objects with Ring Systems
Category:Objects Not in Hydrostatic Equilibrium
Category:Objects with No Atmosphere
Category:Numbered Objects
Category:Numbered Minor Planets
Category:Centaur
Category:Named Objects
Category:Named Minor Planets