Atmosphere retention by terrestrial planets orbiting M dwarfs

Ascertain whether terrestrial planets orbiting M-dwarf stars can retain atmospheres to the present day, given the stars’ elevated activity levels and extended pre-main-sequence phases.

Background

M-dwarf stars have higher activity and longer pre-main-sequence lifetimes than Sun-like stars, leading to enhanced XUV irradiation that threatens atmospheric survival for close-in terrestrial planets.

Despite intensive observational efforts, detections of atmospheres around terrestrial M-dwarf planets have been largely negative or inconclusive, and the authors explicitly state that whether such planets can retain atmospheres to the present day remains unclear.