Simulation of the spin evolution of some selected exoplanets and inferences on their climate

TL;DR

This study uses VPLanet to simulate the spin evolution of select exoplanets, assessing their potential climate and habitability based on their likely spin states influenced by tidal interactions.

Contribution

It provides new insights into the spin states of specific exoplanets and their implications for climate and habitability, especially for planets with uncertain spin conditions.

Findings

Kepler62f, Kepler1126c, Kepler1544b are likely fast rotators.

Kepler186f, Kepler62e, Kepler442b's spin states are indeterminate without eccentricity data.

Kepler440b is expected to be tidally trapped.

Abstract

In this work, using the simulator VPLanet, we analyze the spin evolution of some selected exoplanets due to the tidal interaction with their host star. For a rocky planet, two spin conditions are possible, the trapped rotation and the fast rotation, referring to the cases of achieved and non achieved tidal trapping, respectively. We focus on planets whose spin condition is not obvious, because no study is needed for planets which are undoubtedly fast rotators or undoubtedly trapped rotators; moreover, we consider only exoplanets that are interesting from an astrobiological perspective. The current spin conditions of the considered planets are hypothesized, taking into account the age of the host star. Inferences regarding planetary climate and habitability, which is defined by the possibility of stably sustaining the liquid water on the surface, are also discussed. Results of this work show that Kepler62f, Kepler1126c and Kepler1544b are expected to be fast rotators regardless of the orbital eccentricity; the spin condition of Kepler186f, Kepler62e, and Kepler442b cannot be determined without constraints on the eccentricity, which are currently unavailable; Kepler440b is expected to be tidally trapped.