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arXiv · 1903.05718

EUV influences on exoplanet atmospheric stability and evolution

Allison Youngblood·Kevin France·Tommi Koskinen·Luca Fossati·Ute Amerstorfer·Herbert Lichtenegger·Jeremy Drake·James Mason·Brian Fleming·Joel Allred·Zachory Berta-Thompson·Vincent Bourrier·Cynthia Froning·Cecilia Garraffo·Guillaume Gronoff·Meng Jin·Adam Kowalski·Rachel Osten
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Abstract

The planetary effective surface temperature alone is insufficient to characterize exoplanet atmospheres and their stability or evolution. Considering the star-planet system as a whole is necessary, and a critical component of the system is the photoionizing stellar extreme ultraviolet emission (EUV; 100-912 {\AA}). EUV photons drive atmospheric mass loss through thermal and nonthermal processes, and an accurate accounting of the EUV energy deposition in a planet's energy budget is essential, especially for terrestrial habitable zone planets and close-in gaseous planets. Direct EUV observations of exoplanet host stars would require a new, dedicated observatory. Archival observations from the $\textit{EUVE}$ satellite, models, and theory alone are insufficient to accurately characterize EUV spectra of the majority of exoplanet host stars, especially for low-mass stars.

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Allison Youngblood, Kevin France, Tommi Koskinen, Luca Fossati, Ute Amerstorfer, Herbert Lichtenegger, Jeremy Drake, James Mason, Brian Fleming, Joel Allred, Zachory Berta-Thompson, Vincent Bourrier, Cynthia Froning, Cecilia Garraffo, Guillaume Gronoff, Meng Jin, Adam Kowalski, Rachel Osten. 2019-03-13. EUV influences on exoplanet atmospheric stability and evolution. https://arxiv.org/abs/1903.05718

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