Simulating the Smallest Ring World of Chariklo

A ring system consisting of two dense narrow rings has been discovered around Centaur Chariklo. The existence of these rings around a small object poses various questions, such as their origin, stability, and lifetime. In order to understand the nature of Chariklo's rings, we perform global $N$-body simulations of the self-gravitating collisional particle rings for the first time. We find that Chariklo should be denser than the ring material to avoid the rapid diffusion of the rings. If Chariklo is denser than the ring material, fine spiral structures called self-gravity wakes occur in the inner ring. These wakes accelerate the viscous spreading of the ring significantly and they typically occur on timescales of about $100\,\mathrm{years}$ for m-sized ring particles, which is considerably shorter than the timescales suggested in previous studies. The existence of these narrow rings implies smaller ring particles or the existence of shepherding satellites.