TY - JOUR
T1 - Airy worlds or barren rocks? On the survivability of secondary atmospheres around the TRAPPIST-1 planets
AU - Van Looveren, Gwenaël
AU - Güdel, Manuel
AU - Boro Saikia, Sudeshna
AU - Kislyakova, Kristina
N1 - © The Authors 2024
PY - 2024/3/1
Y1 - 2024/3/1
N2 - In this work we aim to determine the atmospheric survivability of the TRAPPIST-1 planets by modelling the response of the upper atmosphere to incoming stellar high-energy radiation. Through this case study, we also aim to learn more about rocky planet atmospheres in the habitable zone around low-mass M dwarfs. We simulated the upper atmospheres using the Kompot code, a self-consistent thermo-chemical code. Specifically, we studied the atmospheric mass loss due to Jeans escape induced by stellar high-energy radiation. This was achieved through a grid of models that account for the differences in planetary properties, irradiances, and atmospheric properties, allowing the exploration of the different factors influencing atmospheric loss. The present-day irradiance of the TRAPPIST-1 planets would lead to the loss of an Earth's atmosphere within just some 100 Myr. Taking into account the much more active early stages of a low-mass M dwarf, the planets undergo a period of even more extreme mass loss, regardless of planetary mass or atmospheric composition. This indicates that it is unlikely that any significant atmosphere could survive for any extended amount of time around any of the TRAPPIST-1 planets. The assumptions used here allow us to generalise the results, and we conclude that the results tentatively indicate that this conclusion applies to all Earth-like planets in the habitable zones of low-mass M dwarfs.
AB - In this work we aim to determine the atmospheric survivability of the TRAPPIST-1 planets by modelling the response of the upper atmosphere to incoming stellar high-energy radiation. Through this case study, we also aim to learn more about rocky planet atmospheres in the habitable zone around low-mass M dwarfs. We simulated the upper atmospheres using the Kompot code, a self-consistent thermo-chemical code. Specifically, we studied the atmospheric mass loss due to Jeans escape induced by stellar high-energy radiation. This was achieved through a grid of models that account for the differences in planetary properties, irradiances, and atmospheric properties, allowing the exploration of the different factors influencing atmospheric loss. The present-day irradiance of the TRAPPIST-1 planets would lead to the loss of an Earth's atmosphere within just some 100 Myr. Taking into account the much more active early stages of a low-mass M dwarf, the planets undergo a period of even more extreme mass loss, regardless of planetary mass or atmospheric composition. This indicates that it is unlikely that any significant atmosphere could survive for any extended amount of time around any of the TRAPPIST-1 planets. The assumptions used here allow us to generalise the results, and we conclude that the results tentatively indicate that this conclusion applies to all Earth-like planets in the habitable zones of low-mass M dwarfs.
KW - Astrophysics - Earth and Planetary Astrophysics
KW - Planet-star interactions
KW - Planets and satellites: individual: TRAPPIST-1
KW - Planets and satellites: atmospheres
KW - Planets and satellites: terrestrial planets
UR - http://www.scopus.com/inward/record.url?scp=85188011702&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/202348079
DO - 10.1051/0004-6361/202348079
M3 - Article
SN - 0004-6361
VL - 683
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
M1 - A153
ER -