The Lords of the Rings among centaurs

[PF_SpaceNews]

The Lords of the Rings among centaurs

(Phys.org)—Chariklo, the largest known centaur object, orbiting in a region between Saturn and Uranus, is a very intriguing celestial body that surprised astronomers last year. This remote minor planet has unveiled the existence of its rings during a stellar occultation, when it passed in front of a star UCAC4 248-108672. Astronomer José Luis Ortiz from the Institute of Astrophysics of Andalusia in Spain, who was a member of the team that made the discovery, assumes that the ring systems on other minor objects in the solar system could be more common than we think.

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[Greg Bernhardt]

Is there a minimum size of an object for rings to develop?

 

[Janus]

Is there a minimum size of an object for rings to develop?

Well, as an object gets smaller, it can be irregularly shaped while at the same time the distance at which a it can hold to orbiting objects ( its Hill sphere) also shrinks. Thus I would assume that if you go small enough, there will be point that the Hill sphere will shrink into that region where the irregular shape of the object has significant effect on orbiting objects and it will not have any zone where orbits can form.

 

[mfb]

The radius of the Hill sphere for smaller objects is proportional to their radius (at a given density). If we scale the object up and keep the shape the same, the influence of the higher moments of its gravitational field at the border of the Hill sphere will stay the same. The same is true for the Roche limit.

Smaller objects tend to have more irregular shapes, however.