Exploring The Interactions Between The Internal Structure, The Atmosphere And The Tidal Evolution Of Planets Around Low-Mass Stars

EXPLORING THE INTERACTIONS BETWEEN THE INTERNAL STRUCTURE, THE ATMOSPHERE AND THE TIDAL EVOLUTION OF PLANETS AROUND LOW-MASS STARS

 

PI: Prof. Emeline Bolmont

Collaborators: Gabriel Tobie (University of Nantes), Stéphane Mathis (CEA, Saclay), Corinne Charbonnel, Martin Turbet (LMD Paris, LAB Bordeaux)

Funding: SNSF grant N° 200021_197176 & 200020_215760 & PlanetS

Dates: 01/01/2021 – 31/12/2025

Description:

Due to observational biases, a majority of the exoplanets are found very close to their host star. These planets are subjected to star-planet interactions such as tidal interactions. In particular, the planetary tide impacts the orbital distance, eccentricity, obliquity and rotation period of the planet, while it depends on its mass, radius and internal structure. Through tides, a planet’s internal structure shapes the architecture of close-in exoplanets systems. Besides, the tidally evolving quantities, eccentricity and spin, are difficult to observationally measure. Correctly modeling tidal interactions for close-in planets is necessary to better constrain the observed exoplanet population.

Since the discovery of Proxima-b and the TRAPPIST-1 system, planets around low-mass stars have been one of the hottest topics in exoplanet science. These systems represent a unique opportunity to probe the atmosphere of temperate planets. Understanding the habitability of these planets requires to know how their atmosphere and climate evolved. In particular, their climate depends on orbital and rotational tidal evolution, which depends on the internal structure of the planets and on the interactions between the atmosphere and the interior of the planets.

The scientific question this project aims to answer is the following: How do the interactions between a planet’s internal structure, its tidal evolution and its atmosphere influence its climate and habitability, and could we observe it?

Positions:

• One PhD (Alexandre Revol): Tidal rotational and thermal evolution of planets around low-mass stars
• One PhD (Leon Kwok): Evolution of resonant chains of planets under the stellar dynamical tide
• One Computer engineer (Tim Kallioinen): Implementation of good coding practice in the group codes
• One PhD/postdoc (Guillaume Chaverot): Exploration of the inner edge of the habitable zone, the onset of the runaway greenhouse (→10/2023)