Magnetically channeled
wind-shock models are promising (q1 Ori C,
perhaps t Sco): Schulz (2003) has
shown that O stars have these X-ray signatures for less than 1
million years on the main sequence
Normal B stars (like b Cru, B0.5 IV and e CMa B2 II) have very soft X-ray spectra and
narrow lines: wind shocks if the X-ray wind isn’t moving very
fast? Magnetically channeled wind shocks if the shocks aren’t very
strong? Dynamo-driven coronae if our understanding of dynamos is incomplete…