Spectroscopic stellar parameters for 582 FGK stars in the HARPS volume-limited sample. Revising the metallicity-planet correlation

TL;DR

This study provides a high-precision catalog of stellar parameters for 582 FGK stars in the HARPS sample, analyzing their metallicities and revising the correlation between metallicity and planet occurrence.

Contribution

It offers a homogeneous spectroscopic analysis of a volume-limited sample, improving the understanding of stellar parameters and the metallicity-planet connection.

Findings

Higher metallicity stars show increased planet occurrence.

The metallicity distribution differs for planet-hosting stars.

The combined sample includes 1830 stars for robust analysis.

Abstract

To understand the formation and evolution of solar-type stars and planets in the solar neighborhood, we need to obtain their stellar parameters with high precision. We present a catalog of precise stellar parameters for low-activity FGK single stars in a volume-limited sample followed by the HARPS spectrograph in the quest to identify extra-solar planets. The spectroscopic analysis was completed assuming LTE with a grid of Kurucz atmosphere models and using the ARES code to perform an automatic measurement of the line equivalent widths. The results are compared with different independent methods and also with other values found in the literature for common stars. Both comparisons are consistent and illustrate the homogeneity of the parameters derived by our team. The derived metallicities of this sample reveal a somewhat different distribution for the present planet hosts, but still indicates the already known higher frequency of planets observed for the more metal-rich stars. We combine the results derived in this sample with the one from the CORALIE survey to present the largest homogeneous spectroscopic study of the metallicity-giant-planet relation using a total of 1830 stars.