Europlanet Science Congress 2021
Virtual meeting
13 – 24 September 2021
Europlanet Science Congress 2021
Virtual meeting
13 September – 24 September 2021
EPSC Abstracts
Vol. 15, EPSC2021-249, 2021, updated on 21 Jul 2021
https://doi.org/10.5194/epsc2021-249
European Planetary Science Congress 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Mass-Radius relationships of small, highly irradiated exoplanets with small water mass fractions

Hugo Vivien1, Artem Aguichine1, Olivier Mousis1, Magali Deleuil1, and Emmanuel Marcq2
Hugo Vivien et al.
  • 1Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France
  • 2LATMOS/IPSL, UVSQ Université Paris-Saclay, Sorbonne Université, CNRS, Guyancourt, France

This work aims to determine the mass-radius rela-tionships of highly irradiated (500< Tirr<2000K)small planets (0.2<M<2.3M⊕) with water con-tents up to 5%. To do so, we coupled an internalmodel of small terrestrial planets (Brugger et al.,2017) to the atmosphere model elaborated by Marcqet al. (2017, 2019), following the approach depictedin Aguichine et al. (2021) and Mousis et al. (2020).

We show that these planets, even with smallwater contents, can become strongly inflated andproduce large radii for small masses.We alsoshow that strongly irradiated small planets cannotsustain their atmospheres due to the lack of hy-drostatic stability, implying they cannot preserveany hydrosphere. The temperature and the watermass fraction are the key parameters controllingthe extent of inflation and the thickness of thesupercritical layer. An important amount of wateralso leads to the contraction of the rocky interior.However, the composition of the rocky interioronly has a limited impact on the final mass-radiusrelationship, and barely impacts the behavior of thehydrosphere.

How to cite: Vivien, H., Aguichine, A., Mousis, O., Deleuil, M., and Marcq, E.: Mass-Radius relationships of small, highly irradiated exoplanets with small water mass fractions, European Planetary Science Congress 2021, online, 13–24 Sep 2021, EPSC2021-249, https://doi.org/10.5194/epsc2021-249, 2021.

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