Rings of non-spherical, axisymmetric bodies

TL;DR

This study models the dynamics of planetary rings around non-spherical, axisymmetric bodies using a new N-body simulation code, revealing how the body's shape influences ring properties like thickness, impact frequency, and density.

Contribution

We developed a novel self-gravitating N-body simulation method to analyze how non-spherical central bodies affect ring dynamics, extending understanding beyond spherical models.

Findings

Ring properties vary significantly with the shape of the central body.

The gravitational potential influences impact frequency and ring thickness.

Differences observed between rings around large and small bodies like Saturn and Chariklo.

Abstract

We investigate the dynamical behavior of rings around bodies whose shapes depart considerably from that of a sphere. To this end, we have developed a new self-gravitating discrete element N-body code, and employed a local simulation method to simulate a patch of the ring. The central body is modeled as a symmetric (oblate or prolate) ellipsoid, or defined through the characteristic frequencies (circular, vertical, epicyclic) that represent its gravitational field. Through our simulations we explore how a ring's behavior -- characterized by dynamical properties like impact frequency, granular temperature, number density, vertical thickness and radial width -- varies with the changing gravitational potential of the central body. We also contrast properties of rings about large central bodies (e.g. Saturn) with those of smaller ones (e.g. Chariklo). Finally, we investigate how the characteristic frequencies of a central body, restricted to being a solid of revolution with an equatorial plane of symmetry, affect the ring dynamics. The latter process may be employed to qualitatively understand the dynamics of rings about any symmetric solids of revolution.