Elemental Abundances and Atmospheric Parameters of Seven F-G Supergiants

Abstract

Spectroscopic abundance determinations for a sample of seven F-G stars have been carried out. The majority of them have large galactic latitudes. One objective in deriving spectroscopic abundances is to differentiate evolved objects seen at high galactic latitudes from the young population I supergiant stars that happened to have large galactic latitudes but actually belong to the galactic disk. Secondly, it is important to get good calibrators for photometric metallicity indices. It has been suggested in the past that many high galactic latitude F-G stars that are classified as supergiants are in reality subgiants or dwarfs. Our spectroscopically derived gravities show that two of the stars studied in this paper, HR 5165 and HD 114520, are not supergiants as classified in Bright Star Catalogue but are subgiants belonging to the solar neighbourhood. In our sample, HR 3229 and HR 8470 display solar abundances and the derived gravities support the bright giant luminosity class ascribed to them. HR 4114, HR 4912 and HR 7671 have abundances significantly different from those of young supergiants of galactic disk. The evolutionary status of these objects is discussed. (SECTION: Stars)