belongs to a class of objects called Centaurs
—bodies in the outer region of the solar system with unstable orbits and characteristics of both asteroids and comets. Now Felipe Braga-Ribas of the National Observatory in Rio de Janeiro, Brazil, and his colleagues have discovered that Chariklo has rings around it. While watching the object's occultation
of a distant star, they noticed there were smaller dips in the star's brightness both before and after Chariklo passed, which could only be explained by the presence of rings. The presence of rings also explains why Chariklo's chemical makeup appeared to change over time: As the rings rotate, they present a wider or thinner band of material to the observer. Whether the rings are stable is still unknown. Because Chariklo is just 250 km in diameter, its gravity is relatively low, so the presence of other nearby objects could easily disturb its rings.