Assessment of different formation scenarios for the ring system of (10199) Chariklo

Abstract

The discovery that the centaur (10199) Chariklopossesses a ring system opens questions about their origin.We here asses the plausibility of different scenarios for the originof the observed ring system. We first consider the possibility that the material of the ringoriginated in the disruption of a satellite that had reached a criticaldistance from the centaur. We discuss the conditions for the putativesatellite to approach the centaur as a consequence of tidalinteraction. A three-body encounter is also considered as a transportmechanism. In addition, we study the case in which the ring is formedby the ejecta of a cratering collision on the centaur and weconstrain the collision parameters and the size of the resultingcrater of the event. Finally, weconsider that the ring material originates from a catastrophiccollision between a background object and a satellite located at adistance corresponding to the the current location of the ring.We compute the typical timescales for these scenarios. We estimate that in order to be tidally disrupted a satellitewould have had to be larger than approximately 6.5km at the locationof the rings. However the tidal interaction is rather weak for objectsof the size of outer solar system bodies at the ring location,therefore we considered other more effective mechanisms by which asatellite migt have approached the centaur. Collisonal scenarios are bothphysically plausible for the formation, but semianalyticalestimations indicate that the probability of thecorresponding collisions is low under current conditions.