CoRoT's view on the variability of O stars: new theoretical challenges

The CoRoT satellite reveals diverse causes of intrinsic variability in a sample of 6 O-type stars: beta Cep-like pulsation modes in HD 46202 and HD 47129, sun-like oscillations in HD 46149, and red noise in the hottest targets observed (HD 46150, HD 46223, and HD 46966). A preliminary comparison with stellar models points out several shortcomings and questions to be resolved. An excitation problem is encountered for HD 46202. The physical cause of the existence of red noise is unknown, and the reasons why a behaviour is observed in some targets and not in other ones have not been investigated yet. That requires an in-depth description of the outer layers of the objects. In addition, a fine tuning of the asteroseismic modelling is needed for all three stars with stellar pulsation detected.