Apparently Unusual Abundances in Early Type Stars

Abstract

There are five early type stars known in which the hydrogen lines are very weak or absent and in which the helium lines are strong. All these stars are apparently faint and three are at unfavourable declinations for observation from the northern hemisphere. They are listed in Table 26 together with some general information about each. A detailed analysis of the spectrum of HD 168476, of HD 124448, and of BD+10°2179 has been made by Hill (1964, 1965) who used high-dispersion spectrograms obtained at the Radcliffe Observatory and the equivalent widths measured by Klemola (1961) from Lick coudé spectrograms. A little quantitative information from high-dispersion spectrograms has been given by Berger and Greenstein (1963) about BD +13°3224. Aller (1954) has given some information about HD 160641.