Quantitative spectroscopy of extreme helium stars - Model atmospheres and a non-LTE abundance analysis of BD+10${}^{\circ }$2179?

Thomas Kupfer, Norbert Przybilla, Ulrich Heber +3

Extreme helium stars (EHe stars) are hydrogen-deficient supergiants of spectral type A and B. They are believed to result from mergers in double degenerate systems. In this paper w…