The Impact of Stellar Abundance Variations on Stellar Habitable Zone Evolution

TL;DR

This paper investigates how variations in stellar element abundances, especially oxygen to iron ratios, significantly influence stellar evolution and the duration of habitable zones around stars.

Contribution

It introduces stellar models with diverse compositions reflecting observed abundance variations and analyzes their impact on habitable zone evolution.

Findings

Variation in [O/Fe] greatly affects habitability lifetimes.

Stellar evolution is sensitive to non-solar abundance ratios.

Habitability durations can differ by gigayears due to abundance variations.

Abstract

The high quality spectra required for radial velocity planet searches are well-suited to providing abundances for a wide array of elements in large samples of stars. Abundance ratios of the most common elements relative to Fe are observed to vary by more than a factor of two in planet host candidates. This level of variation has a substantial impact on the evolution of the host star and the extent of its habitable zone. We present stellar models of 1 solar mass stars with custom compositions representing the full range of these non-solar abundance ratios. We find that the effects derived from variation over the observed range of [O/Fe] are particularly dramatic. Habitability lifetimes for some classes of orbits can vary by gigayears for the observed range in [O/Fe].