Séminaire IPAG

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Earth-like planets around cool stars: Do they have atmospheres? clouds? oceans?

jeudi 10 mars 2022 - 11h00

Martin Turbet - LMD/ Univ Genève
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Rocky planets in temperate orbits around cool M stars are our best opportunity in the coming years to access via telescopic observations the true nature of exoplanets similar (at least in mass, size and insolation) to Earth. I will present some recent results – obtained with the ‘LMD-Generic GCM’, a state-of-the-art 3-D Global Climate Model for (exo-)planets, that we mainly develop at the LMD and in several French laboratories -- that allow us to better understand what these worlds could look like. Can they have atmospheres? clouds? oceans? I will focus on the famous seven TRAPPIST-1 planets, which provide a unique natural laboratory for testing with observations our current understanding of planetary climates. Specifically, I will present our recent TRAPPIST-1 planet density measurements, whose exquisite accuracy is already putting interesting constraints on their composition and water mass fractions. I will also discuss the prospects for characterizing the atmospheres of these planets using thermal emission and transmission spectroscopy with the JWST, as well as ground-based spectrographs for which the IPAG exoplanet team is at the forefront.

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Hôtes : Xavier Bonfils

Salle Manuel Forestini, 414 rue de la piscine, 38400 Saint Martin d'Hères