A Catalog of Stellar Evolution Profiles and the Effects of Variable Composition on Habitable Systems

TL;DR

This paper provides detailed stellar evolution models across various metallicities and compositions, analyzing how these factors influence habitable zone boundaries and the potential for life development on orbiting planets.

Contribution

It introduces a comprehensive grid of stellar evolution models that incorporate variable chemical compositions to assess habitable zone evolution over time.

Findings

Habitable zone boundaries depend strongly on stellar mass, temperature, and luminosity.

The range of continuously habitable orbits varies with stellar composition.

Chemical characterization of host stars is crucial for assessing planetary habitability.

Abstract

We present stellar evolution models for 0.5 - 1.2 \Msol at scaled metallicities of 0.1 - 1.5 Z\sol and O/Fe values of 0.44 - 2.28 O/Fe\sol. The time dependent evolution of habitable zone boundaries are calculated for each stellar evolution track based on stellar mass, effective temperature, and luminosity parameterizations. The rate of change of stellar surface quantities and the surrounding habitable zone position are strong functions of all three quantities explored. The range of orbits that remain continuously habitable, or habitable for at least 2 Gyr, are provided. The results show that the detailed chemical characterization of exoplanet host stars and a consideration of their evolutionary history are necessary to assess the likelihood that a planet found in the instantaneous habitable zone has had sufficient time to develop a biosphere capable of producing detectable biosignatures. This model grid is designed for use by the astrobiology and exoplanet communities to efficiently characterize the time evolution of host stars and their habitable zones for planetary candidates of interest.