Impacts of stellar evolution and dynamics on the habitable zone: The role of rotation and magnetic activity

TL;DR

This study investigates how stellar evolution, rotation, and magnetic activity influence the habitable zone's location and duration, emphasizing the significant effects of stellar mass and metallicity, especially around low-mass stars.

Contribution

It provides a systematic analysis of the dependence of habitable zone limits on stellar parameters and activity, incorporating stellar evolution models to improve habitability estimations.

Findings

Mass and metallicity greatly affect habitable zone limits.

Stellar rotation has minimal impact on habitable zone boundaries.

Magnetic activity influences habitability around M dwarf stars.

Abstract

In this article, we aim to provide the community with the dependence of the habitable zone upon the stellar mass, metallicity, rotation, and for various prescriptions of the limits of the habitable zone. We use the STAREVOL code to study the evolution of the habitable zone and of the continuously habitable zone limits. Mass and metallicity are the stellar parameters that have the most dramatic effects on the habitable zone limits. Conversely, for a given stellar mass and metallicity, stellar rotation has only a marginal effect on these limits and does not modify the width of the habitable zone. The evolution of the habitable zone limits is also correlated to the evolution of the stellar activity (through the Rossby number) that depends on the stellar mass considered. While the magnetic activity has negligible consequence in the case of more massive stars, these effects may have a strong impact on the habitability of a planet around M dwarf stars. Thus, stellar activity cannot be neglected and may have strong impacts on the development of life during the early stage of the continuously habitable zone phase of low-mass stars. Using observed trends of stellar magnetic field strength we also constrain the planetary magnetic field (at the zero order) required for a sufficient magnetospheric protection during the whole stellar evolution. We explicit for the first time the systematic dependence of planet habitability on stellar parameters along the full evolution of low- and intermediate-mass stars. These results can be used as physical inputs for a first order estimation of exoplanetary habitability.