UV Surface Environments and Atmospheres of Earth-like Planets Orbiting White Dwarfs

TL;DR

This study models the UV surface environments and atmospheric chemistry of Earth-like planets orbiting white dwarfs, revealing how stellar evolution impacts planetary habitability over billions of years.

Contribution

It introduces a coupled climate-photochemistry model to simulate atmospheres of Earth-like planets around white dwarfs across different stellar ages.

Findings

UV environments vary significantly during white dwarf evolution.

Atmospheric composition and surface UV levels change over billions of years.

Implications for habitability depend on stellar temperature and evolution stage.

Abstract

An Earth-like exoplanet orbiting a white dwarf would be exposed to different UV environments than Earth, influencing both its atmospheric photochemistry and UV surface environment. Using a coupled 1D climate-photochemistry code we model atmospheres of Earth-like planets in the habitable zone of white dwarfs for surface temperatures between 6000 K and 4000 K, corresponding to about 7 billion years of white dwarf evolution, as well as discuss the evolution of planetary models in the habitable zone during that evolution.