Abundance analysis of targets for the COROT / MONS asteroseismology missions II. Abundance analysis of the COROT main targets

TL;DR

This study performs detailed chemical abundance analyses of potential COROT asteroseismology targets, validating methods and constraining stellar parameters for slow rotators to support mission planning.

Contribution

It provides a comprehensive abundance analysis of COROT target stars using semi-automatic software and classical methods, validating the reliability of these techniques for slow rotators.

Findings

Good agreement between VWA and classical methods for abundance analysis.

Systematic errors minimized by referencing solar spectra.

Atmospheric parameters constrained within specified uncertainties for slow rotators.

Abstract

One of the goals of the ground-based support program for the COROT and Roemer satellite missions is to characterize suitable target stars for the part of the missions dedicated to asteroseismology. We present the detailed abundance analysis of nine of the potential COROT main targets using the semi-automatic software VWA. For two additional COROT targets we could not perform the analysis due to the high rotational velocity of these stars. For five stars with low rotational velocity we have also performed abundance analysis by a classical equivalent width method in order to test the reliability of the VWA software. The agreement between the different methods is good. We find that it is necessary to measure abundances extracted from each line relative to the abundances found from a spectrum of the Sun in order to remove systematic errors. We have constrained the global atmospheric parameters Teff, log g, and [Fe/H] to within 70-100 K, 0.1-0.2 dex, and 0.1 dex for five stars which are slow rotators (v sin i < 15 km/s). For most of the stars stars we find good agreement with the parameters found from line depth ratios, H-alpha lines, Str\"omgren indices, previous spectroscopic studies, and also log g determined from the HIPPARCOS parallaxes. For the fast rotators v sin i > 60 km/s it is not possible to constrain the atmospheric parameters.