spacetoday.net: Astronomers discover rings around small body in outer solar system

Posted: Thu, Mar 27, 2014, 6:56 AM ET (1056 GMT)
Chariklo rings illustration (ESO)

Astronomers announced Wednesday the discovery of a a pair of rings orbiting a small body in the outer solar system, the first time rings have been discovered around an object other than a planet. Astronomers detected the rings during an occultation of Chariklo, a small body known as a Centaur that orbits between Saturn and Uranus. As Chariklo passed in front of a star, as seen by observers in South America in 2013, they also detected dips in starlight that, astronomers conclude, are caused by two narrow but dense rings orbiting the body. The rings, seven and three kilometers wide, and separated by nine kilometers, orbit Chariklo, a body only 250 kilomters in diameter. Astronomers hypothesize that a collision created the rings, which are held in place by small shepherding moons not detected in the occultation observations.