We all are used to the idea that planets can have rings.
However, looks like rings are far more common object than we thought.
Meet Chariklo - an object known as centaur. "Centaur" is a body between Jupiter and Pluto with characteristics common to both asteroids and comets. Today, there are more than 200 known centaurs, and scientists estimate that there are more than 44,000 of these hybrid asteroid-comets in the solar system.
Chariklo orbits the Sun between Saturn and Uranus, grazing the orbit of Uranus. On 26 March 2014, astronomers announced the discovery of two rings (nicknamed Oiapoque and Chuí) around Chariklo by observing a stellar occultation, making it the first minor planet known to have rings. Chariklo is named after the nymph Chariclo (Χαρικλώ), the wife of Chiron and the daughter of Apollo.
A stellar occultation in 2013 revealed that Chariklo has two rings with radii 396 and 405 km and widths of about 7 km and 3.5 km respectively. The rings are approximately 9 km apart. This makes Chariklo the smallest known object to have rings. These rings are consistent with an edge-on orientation in 2008, which can explains Chariklo's dimming before 2008 and brightening since. Nonetheless, the elongated shape of Chariklo explain most of the brightness variability resulting in darker rings than previously determined. Furthermore, the rings can explain the gradual disappearance of the water-ice features in Chariklo's spectrum before 2008 and their reappearance thereafter if the water ice is in Chariklo's 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.
Image: European Southern Observatory