Fractionated stellar wind and the H / He abundance anomalies in Bp stars

Radiatively driven winds occur in all main sequence stars (Babel 1995, 1996). However, due to the weak coupling between the photon absorbing metals and the inert elements H and He, the wind in the low temperature domain is fractionated: He decouples from the wind at Teff < 25 000 K, and below 17 000 K even H. The decoupled elements fall back to the surface… CONTINUE READING