Atmospheres and UV Environments of Earth-like Planets Throughout Post-Main Sequence Evolution

Abstract

During the post-main sequence phase of stellar evolution the orbital distance of the habitable zone, which allows for liquid surface water on terrestrial planets, moves out past the system's original frost line, providing an opportunity for outer planetary system surface habitability. We use a 1D coupled climate/photochemistry code to study the impact of the stellar environment on the planetary atmospheres of Earth-like planets/moons throughout its time in the post-main sequence habitable zone. We also explore the ground UV environments of such planets/moons and compare them to Earth's. We model the evolution of star-planet systems with host stars ranging from 1.0 to 3.5 M${}_{\odot }$ throughout the post-main sequence, calculating stellar mass loss and its effects on planetary orbital evolution and atmospheric erosion. The maximum amount of time a rocky planet can spend continuously in the evolving post-MS habitable zone ranges between 56 and 257 Myr for our grid stars. Thus, during the post-MS evolution of their host star, subsurface life on cold planets and moons could become remotely detectable once the initially frozen surface melts. Frozen planets or moons, like Europa in our Solar System, experience a relatively stable environment on the horizontal branch of their host stars' evolution for millions of years.

23 pages, 7 figures, 10 tables

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Cited by in corpus (9)

• Is ozone a reliable proxy for molecular oxygen? I. The O2-O3 relationship for Earth-like atmospheres
• Expanding the Timeline for Earth's Photosynthetic Red Edge Biosignature
• Past, Present and Future Stars that can see Earth as a Transiting Exoplanet
• H${}_2$-dominated Atmosphere as an Indicator of Second-generation Rocky White Dwarf Exoplanets
• The grain size survival threshold in one-planet post-main-sequence exoplanetary systems
• Which Stars can see Earth as a Transiting Exoplanet?
• Planetary magnetosphere evolution around post-main-sequence stars
• High resolution Spectra of Earth-Like Planets Orbiting Red Giant Host Stars
• The Color of Habitability