Magnetically channeled wind-shock models are promising (q1 Ori C, perhaps t
Sco): Schulz (AAS, 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) have very soft X-ray spectra and narrow lines: wind shocks if the
X-ray wind isnŐt
moving very fast? Magnetically channeled wind shocks if the shocks arenŐt very
strong? Dynamo-driven coronae if our understanding of dynamos is incompleteÉ