Exogeology from Polluted White Dwarfs

TL;DR

This paper discusses how observing polluted white dwarfs allows scientists to infer the composition and geology of exoplanetary bodies, offering insights into distant planetary interiors that are otherwise difficult to study.

Contribution

It introduces a method of studying exoplanetary geology through spectroscopic analysis of white dwarf pollution, revealing planetary compositions indirectly.

Findings

White dwarf pollution reflects rocky, icy, and carbonaceous planetary fragments.

Spectroscopic signatures enable inference of exoplanetary interior composition.

White dwarf systems serve as natural laboratories for exogeology.

Abstract

It is difficult to study the interiors of terrestrial planets in the Solar System and the problem is magnified for distant exoplanets. However, sometimes nature is helpful. Some planetary bodies are torn to fragments and consumed by the strong gravity close to the descendants of Sun-like stars, white dwarfs. We can deduce the general composition of the planet when we observe the spectroscopic signature of the white dwarf. Most planetary fragments that fall into white dwarfs appear to be rocky with a variable fraction of associated ice and carbon. These white dwarf planetary systems provide a unique opportunity to study the geology of exoplanetary systems.