Homogeneous model for the TRAPPIST-1e planet with an icy layer

TL;DR

This study demonstrates that a homogeneous planet model with Sundberg-Cooper rheology can effectively replicate the tidal dissipation behavior of a multilayered icy planet like TRAPPIST-1e, simplifying modeling efforts.

Contribution

The paper introduces the use of Sundberg-Cooper rheology in homogeneous models to accurately approximate multilayered icy planets' tidal responses.

Findings

Homogeneous models with Sundberg-Cooper rheology match multilayered models' dissipation rates.

A single rheological model can replace complex multilayered structures for tidal analysis.

The approach simplifies the estimation of tidal dissipation in icy exoplanets.

Abstract

In this work we investigate whether a multilayered planet can be approximated as a homogeneous planet, and in particular how well the dissipation rate of a multilayered planet can be reproduced with a homogeneous rheology. We study the case of a stratified body with an icy crust that, according to recent studies, displays a double peak feature in the tidal response that cannot be reproduced with a homogeneous planet with an Andrade rheology. We revisit the problem with a slightly more complex rheology for the homogeneous body, the Sundberg-Cooper rheology, which naturally has a double peak feature, and apply the model to the TRAPPIST-1e planet. Our results compare very well with the results obtained when employing a multilayered model, showing that it is possible to approximate the behavior of a multilayer icy planet with a homogeneous planet using the Sundberg-Cooper rheology. This highlights the fact that we do not need the complexity of the multilayer planet model in order to estimate the tidal dissipation of an icy planet.