A couple of weeks ago, the ESO announced that they had discovered rings around an asteroid. They observed an occultation of starlight during Chariklo 10199’s passing, and the resulting light curve was symmetrical and indicative of a double ring system. Chariklo is small and not perfectly spherical. It was discovered in 1997, but this has been the first oppurtunity to image it. It is small enough that it’s escape velocity could be attained by a fast car(350km/s). The mechanism by which is gained rings is as yet unknown. It is possible that a collision with another object released debris into orbit. Prior to the discovery of the rings, a spectral signature for water ice was detected, and it is now thought that ice and dust in the rings are responsible. In the future a search may continue for shepherd moons or other small satellites that may be associated with the rings.
At 248 km in diameter, it is the largest Centaur yet discovered. Centaurs are a special class of small object in our solar system that cross orbit with the giant planets. They are not expected to keep these orbits. They remain stable for estimated times on the order of millions of years before a gravitational interaction with one of the giant planets, or less probably, a collision disturbs their orbit. Chariklo is very near to 4:3 resonance with Uranus, and so it’s orbit is relatively stable as compared to other centaurs.
http://www.eso.org/public/news/eso1410/
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“JPL Small-Body Database Browser: 10199 Chariklo (1997 CU26)”. 2008-07-03. Retrieved 2008-10-21.
Braga-Ribas, F.; Sicardy, B.; Ortiz, J. L.; Snodgrass, C.; Roques, F.; Vieira-Martins, R.; Camargo, J. I. B.; Assafin, M.; Duffard, R.; Jehin, E.; Pollock, J.; Leiva, R.; Emilio, M.; Machado, D. I.; Colazo, C.; Lellouch, E.; Skottfelt, J.; Gillon, M.; Ligier, N.; Maquet, L.; Benedetti-Rossi, G.; Gomes, A. R.; Kervella, P.; Monteiro, H.; Sfair, R.; Moutamid, M. E.; Tancredi, G.; Spagnotto, J.; Maury, A. et al. (2014). “A ring system detected around the Centaur (10199) Chariklo”. Nature 508 (7494): 72. doi:10.1038/nature13155.
