Abundance analysis of targets for the COROT/MONS asteroseismology missions^*

I. Semi-automatic abundance analysis of the γ Dor star HD 49434

¹ Institute for Physics and Astronomy, University of Aarhus, Bygn. 520, 8000 Aarhus C, Denmark
² Laboratoire d'Astrophysique de l'OMP, CNRS UMR 5572, Observatoire Midi-Pyrénées, 14 avenue Édouard Belin, 31400 Toulouse, France
³ Laboratoire d'Astrophysique de Marseille, France
⁴ Instituto de Astrofísica de Andaluciá, Spain
⁵ Institut für Astronomie, Universität Wien, Türkenschanzstrasse 17, 1180 Wien, Austria
⁶ Observatoire de Paris, France

Corresponding author: H. Bruntt, bruntt@ifa.au.dk

Received: 23 January 2002
Accepted: 5 April 2002

Abstract

One of the goals of the ground-based support program for the COROT and MONS/Rømer satellite missions is to select and characterise suitable target stars for the part of the missions dedicated to asteroseismology. While the global atmospheric parameters may be determined with good accuracy from the Strömgren indices, careful abundance analysis must be made for the proposed main targets. This is a time consuming process considering the long list of primary and secondary targets. We have therefore developed new software called vwa for this task. The vwa automatically selects the least blended lines from the atomic line database vald, and consequently adjusts the abundance in order to find the best match between the calculated and observed spectra. The variability of HD 49434 was discovered as part of COROT ground-based support observations. Here we present a detailed abundance analysis of HD 49434 using vwa. For most elements we find abundances somewhat below the Solar values, in particular we find [Fe/H] . We also present the results from the study of the variability that is seen in spectroscopic and photometric time series observations. From the characteristics of the variation seen in photometry and in the line profiles we propose that HD 49434 is a variable star of the γ Doradus type.