On the Stability of the Satellites of Asteroid 87 Sylvia

TL;DR

This study investigates the orbital stability of Sylvia's moonlets Romulus and Remus, revealing that their orbits are stabilized by Sylvia's oblateness despite resonances with the Sun and Jupiter.

Contribution

It provides a detailed analysis of the dynamical stability of Sylvia's satellites, highlighting the stabilizing effect of Sylvia's oblateness on their orbits.

Findings

Satellites are in secular resonance with each other.

Orbital inclinations exhibit long-term oscillations influenced by the Sun and Jupiter.

Including Sylvia's oblateness stabilizes the satellites' orbits.

Abstract

he triple asteroidal system (87) Sylvia is composed of a 280-km primary and two small moonlets named Romulus and Remus (Marchis et al 2005). Sylvia is located in the main asteroid belt. The satellites are in nearly equatorial circular orbits around the primary. In the present work we study the stability of the satellites Romulus and Remus, in order to identify the effects and the contribution of each perturber. The results from the 3-body problem, Sylvia-Romulus-Remus, show no significant variation of their orbital elements. However, the inclinations of the satellites present a long period evolution, when the Sun is included in the system. Such amplitude is amplified when Jupiter is included. An analysis of these results show that Romulus and Remus are librating in a secular resonance and their longitude of the nodes are locked to each other. The satellites get caught in an evection resonance with Jupiter. However, the orbital evolutions of the satellites became completely stable when the oblateness of Sylvia is included in the simulations.