Close binary EHB stars from SPY
arXiv:astro-ph/0401201 · doi:10.1023/B:ASTR.0000044362.07416.6c
Abstract
We present the results of a radial velocity (RV) survey of 46 subdwarf B (sdB) and 23 helium-rich subdwarf O (He-sdO) stars. We detected 18 (39%) new sdB binary systems, but only one (4%) He-sdO binary. Orbital parameters of nine sdB and sdO binaries, derived from follow-up spectroscopy, are presented. Our results are compared with evolutionary scenarios and previous observational investigations.
To appear in "Extreme Horizontal Branch Stars and Related Objects", Astrophysics and Space Science, Kluver Academic Publishers, edited by P.F.L. Maxted