Parent Stars of Extrasolar Planets. IX. Lithium Abundances

TL;DR

This study compares lithium abundances in stars with and without planets, finding that stars with planets tend to have lower lithium levels, which correlates with rotation and activity anomalies, suggesting planet formation impacts stellar properties.

Contribution

It provides the first consistent comparison showing lower lithium in planet-hosting stars and links this to stellar rotation and activity, indicating planet formation influences stellar evolution.

Findings

Stars with planets have lower lithium abundances near solar temperature.

Li abundance anomalies correlate with vsini and $R^{'}_{HK}$ anomalies.

Planet formation may alter stellar rotation and lithium levels.

Abstract

We compare the Li abundances of a sample of stars with planets discovered with the Doppler method to a sample of stars without detected planets. We prepared the samples by combining the Li abundances reported in several recent studies in a consistent way. Our results confirm recent claims that the Li abundances of stars with planets are smaller than those of stars without planets near the solar temperature. We also find that the vsini and $R^{'}_{\rm HK}$ anomalies correlate with the Li abundance anomalies. These results suggest that planet formation processes have altered the rotation and Li abundances of stars that host Doppler detected planets. We encourage others to test these findings with additional observations of Li in stars with temperatures between 5600 and 6200 K.