Small particles in Pluto's environment: effects of the solar radiation pressure

TL;DR

This study models how solar radiation pressure influences dust particles ejected from Nix and Hydra, forming a transient ring around Pluto with specific optical properties, and assesses particle lifetimes and ring stability.

Contribution

It provides a detailed numerical analysis of dust particle dynamics under radiation pressure around Pluto, estimating ring properties and particle lifetimes for the first time.

Findings

Particles form a 16,000 km wide ring around Pluto.

Approximately 50% of 1-micron particles are removed annually due to collisions.

A very tenuous ring with optical depth of 6×10⁻¹¹ can be sustained.

Abstract

Impacts of micrometeoroids on the surfaces of Nix and Hydra can produced dust particles and form a ring around Pluto. However, dissipative forces, such as the solar radiation pressure, can lead the particles into collisions in a very short period of time. In this work we investigate the orbital evolution of escaping ejecta under the effects of the radiation pressure force combined with the gravitational effects of Pluto,Charon, Nix and Hydra. The mass production rate from the surfaces of Nix and Hydra was obtained from analytical models. By comparing the lifetime of the survived particles, derived from our numerical simulations, and the mass of a putative ring mainly formed by the particles released from the surfaces of Nix and Hydra we could estimate the ring normal optical depth. The released particles, encompassing the orbits of Nix and Hydra, temporarily form a 16000 km wide ring. Collisions with the massive bodies, mainly due to the effects of the radiation pressure force, remove about 50% of the $1\mu$m particles in 1 year. A tenuous ring with a normal optical depth of $6 \times 10^{-11}$ can be maintained by the dust particles released from the surfaces of Nix and Hydra.