Determination of the spectroscopic stellar parameters for 257 field giant stars

TL;DR

This paper provides a detailed catalogue of stellar atmospheric parameters and iron abundances for 257 evolved field stars, aiding studies of planet formation and stellar evolution.

Contribution

It offers new, precise spectroscopic measurements for 190 stars and compares different line-list methods to ensure accuracy.

Findings

Good agreement with previous literature for known stars.

Small differences among line-list methods for most stars.

New measurements for 190 stars not previously published.

Abstract

The study of stellar parameters of planet-hosting stars, such as metallicity and chemical abundances, help us to understand the theory of planet formation and stellar evolution. Here, we present a catalogue of accurate stellar atmospheric parameters and iron abundances for a sample of 257 K and G field evolved stars that are being surveyed for planets using precise radial--velocity measurements as part of the CORALIE programme to search for planets around giants. The analysis was done using a set of high--resolution and high--signal-to-noise Ultraviolet and Visible Echelle Spectrograph spectra. The stellar parameters were derived using Fe I and II ionization and excitation equilibrium methods. To take into account possible effects related to the choice of the lines on the derived parameters, we used three different iron line-list sets in our analysis, and the results differ among themselves by a small factor for most of stars. {For those stars with previous literature parameter estimates, we found very good agreement with our own values.} In the present catalogue we are providing new precise spectroscopic measurements of effective temperature, surface gravity, microturbulence, and metallicity for 190 stars for which it has not been found or published in previous articles.