The determination of element abundances in the solar neighborhood from B-type stellar spectra. I - Argon

Abstract

The coude spectrograph and CCD camera on the coude feed telescope at the Kitt Peak National Observatory, have been used to obtain high-resolution (0.09 A FWHM), high signal-to-noise (200) observations of weak A II absorption lines formed in the atmospheres of main-sequence early-type stars. These have been analyzed using LTE model atmosphere techniques to derive a mean argon-to-hydrogen abundance ratio of 6.49, which is believed to be accurate to + or - 0.1 dex. As the stellar atmospheres should be uncontaminated by the products of interior reactions, this abundance should be that of the interstellar medium from which the stars formed some 1-10 million yrs ago, and hence reflects the current chemical composition of the solar neighborhood. The result is compatible with that of Veck and Parkinson (1981).