Elemental abundance analyses with DAO spectrograms: XL

Abstract

We continue our series of high‐quality fine analyses of slowly and moderately rotating normal and peculiar Main Sequence Band B, A, and F stars. We use Kurucz's ATLAS9 model atmospheres in Local Thermodynamic Equilibrium and WIDTH9 codes and high signal‐to‐noise (>200) spectrograms currently obtained with a charge‐coupled device detectors on the long camera of the Coudé spectrograph of the 1.22‐m telescope of the Dominion Astrophysical Observatory. We were surprised that the elemental abundances of the A2 V star HR 196 indicated that it was slightly metal‐poor relative to the Sun. Its projected rotational velocity is 36±2 km s−1. Its abundances are for the most part close to those of α Dra (A0 III), a star with less than solar abundances. We found that the B8 V star HR 6968 ( km s−1) was a peculiar member of the HgMn class with elemental abundances somewhat similar to those of 53 Tau. Most significantly, it has an overabundance of Mn, and Hg II λ3984 is absent. Our analysis of the sharp‐lined ( km s−1) HgMn star HR 7664 is an improvement of the earlier co‐added photographic study of this series, with reduced scatter about the mean abundance for each atomic species. Further, we found abundances for several additional atomic species including Xe II.