Parent Stars of Extrasolar Planets. X. Lithium Abundances and vsini Revisited

TL;DR

This study compares lithium abundances and rotational velocities of stars with and without detected exoplanets, confirming that stars with planets tend to have lower values near solar temperature and refining the temperature at which lithium abundance increases.

Contribution

It revises the temperature at which lithium abundance increases in planet-hosting stars and confirms the correlation between lower lithium and vsini in stars with planets.

Findings

Stars with planets have lower Li and vsini near solar temperature.

The Li abundance transition occurs near 5850 K, revised from previous estimates.

The vsini transition occurs near 6000 K, but less precisely constrained.

Abstract

We determine Li abundances and vsini values from new spectra of 53 stars with Doppler-detected planets not included in our previous papers in this series. We also examine two sets of stars without detected planets, which together serve as our comparison sample. Using the method of comparison of Li abundances and vsini values between two sets of stars we introduced in Gonzalez (2008), we confirm that these two quantities are smaller among stars with planets compared to stars without detected planets near the solar temperature. The transition from low to high Li abundance among SWPs occurs near 5850 K, a revision of about 50 K from our previous determination. The transition from low to high vsini occurs near 6000 K, but this temperature is not as well constrained.