Production and fate of the G ring arc particles due to Aegaeon (Saturn LIII)

TL;DR

This study investigates the production, dynamics, and depletion of particles in Saturn's G ring arc, highlighting Aegaeon's role and the influence of solar radiation, with implications for the arc's longevity and particle sources.

Contribution

The paper combines observations and numerical simulations to analyze the interactions between Aegaeon, arc particles, and solar radiation, revealing the limited role of Aegaeon as the sole dust source.

Findings

Aegaeon depletes arc dust via collisions within 40 years.

Solar radiation accelerates dust removal, especially for 10 μm grains.

Aegaeon alone cannot account for the observed arc material over 30,000 years.

Abstract

The G ring arc hosts the smallest satellite of Saturn, Aegaeon, observed with a set of images sent by Cassini spacecraft. Along with Aegaeon, the arc particles are trapped in a 7:6 corotation eccentric resonance with the satellite Mimas. Due to this resonance, both Aegaeon and the arc material are confined to within sixty degrees of corotating longitudes. The arc particles are dust grains which can have their orbital motions severely disturbed by the solar radiation force. Our numerical simulations showed that Aegaeon is responsible for depleting the arc dust population by removing them through collisions. The solar radiation force hastens these collisions by removing most of the 10$~\mu$m sized grains in less than 40 years. Some debris released from Aegaeon's surface by meteoroid impacts can populate the arc. However, it would take 30,000 years for Aegaeon to supply the observed amount of arc material, and so it is unlikely that Aegaeon alone is the source of dust in the arc.