The Origins & Reservoirs of Exocomets

Abstract

Small bodies exist in distinct populations within their planetary systems. These reservoir populations hold a range of compositions, which to first order are dependent on formation location relative to their star. We provide a general overview of the nature of the reservoirs that source exocomets, from the influence of the stellar environment through planetesimal formation to comparisons with Solar System populations. Once transitioned from a young protoplanetary disc to a debris disc, a star can expect to be rained with exocomets. While exocomets are predominantly detected to date at A-type stars, planetesimals plausibly exist across a range of stellar masses, based on exoplanet abundance, debris disc occurrence and white dwarf infall.

Accepted for publication in Space Science Reviews. Chapter written for the the workshop 'Exocomets: Bridging our Understanding of Minor Bodies in Solar and Exoplanetary Systems' (July 2024), at the International Space Science Insitute (ISSI), Bern