Convective settling in main sequence stars: Li and Be depletion

TL;DR

This paper models convective settling in main sequence stars to explain lithium and beryllium depletion, showing good agreement with observed stellar abundances across different ages and masses.

Contribution

It introduces a parametric model of convective settling that accounts for Li and Be depletion dependence on stellar properties, extending previous work on solar Li depletion.

Findings

Model agrees with Li abundances in open clusters and solar twins.

Model is consistent with Be abundances in field stars.

Underestimates Li depletion in the first ~1 Gyr.

Abstract

The process of convective settling is based on the assumption that a small fraction of the low-entropy downflows sink from the photosphere down to the bottom of the star's envelope convection zone retaining a substantial entropy contrast. We have previously shown that this process could explain the slow Li depletion observed in the Sun. We construct a parametric model of convective settling to investigate the dependence of Li and Be depletion on stellar mass and age. Our model is generally in good agreement with the Li abundances measured in open clusters and solar twins, although it seems to underestimate the Li depletion in the first ~1 Gyr. The model is also compatible with the Be abundances measured in a sample of field stars.