The Evolution of Stellar Rotation and the Hydrogen Atmospheres of Habitable-zone Terrestrial Planets

Author(s)
Colin Johnstone, Manuel Güdel, Alexander Stökl, Helmut Lammer, Lin Tu, Theresa Rank-Lüftinger, Ernst Dorfi
Abstract

Terrestrial planets formed within gaseous protoplanetary disks can accumulate significant hydrogen envelopes. The evolution of such an atmosphere due to XUV driven evaporation depends on the activity evolution of the host star, which itself depends sensitively on its rotational evolution, and therefore on its initial rotation rate. In this Letter, we derive an easily applicable method for calculating planetary atmosphere evaporation that combines models for a hydrostatic lower atmosphere and a hydrodynamic upper atmosphere. We show that the initial rotation rate of the central star is of critical importance for the evolution of planetary atmospheres and can determine if a planet keeps or loses its primordial hydrogen envelope. Our results highlight the need for a detailed treatment of stellar activity evolution when studying the evolution of planetary atmospheres.

Organisation(s)
Department of Astrophysics
External organisation(s)
Österreichische Akademie der Wissenschaften (ÖAW)
Journal
The Astrophysical journal Letters
Volume
815
No. of pages
6
ISSN
2041-8205
DOI
https://doi.org/10.1088/2041-8205/815/1/L12
Publication date
12-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/a4e44353-1aa1-410d-8b16-2814588090e3