Lithium abundances in exoplanet-hosts stars

TL;DR

This paper investigates the differences in lithium abundance and metallicity between exoplanet-host stars and stars without detected planets, using stellar models and spectroscopic data to understand their chemical peculiarities.

Contribution

It introduces stellar models with varying parameters to explain lithium depletion and overmetallicity in exoplanet-host stars, comparing scenarios with observational data.

Findings

Exoplanet-host stars are more lithium-depleted than non-host stars.

Overmetallicity in EHS can be explained by different accretion scenarios.

Model results align with spectroscopic observations of lithium abundance.

Abstract

Exoplanet-host stars (EHS) are known to present surface chemical abundances different from those of stars without any detected planet (NEHS). EHS are, on the average, overmetallic compared to the Sun. The observations also show that, for cool stars, lithium is more depleted in EHS than in NEHS. The overmetallicity of EHS may be studied in the framework of two different scenarii. We have computed main sequence stellar models with various masses, metallicities and accretion rates. The results show different profiles for the lithium destruction according to the scenario. We compare these results to the spectroscopic observations of lithium.