CoRoT observations of O stars: diverse origins of variability

R. Blomme, M. Briquet, P. Degroote, L. Mahy, C. Aerts, J. Cuypers, M. Godart, E. Gosset, M. Hareter, J. Montalban, T. Morel, M.F. Nieva, A. Noels, R. Oreiro, E. Poretti, N. Przybilla, M. Rainer, G. Rauw, F. Schiller, S. Simon-Diaz, K. Smolders, P. Ventura, M. Vuckovic, M. Auvergne, A. Baglin, F. Baudin, C. Catala, E. Michel and R. Samadi

R. Blomme: Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussel, Belgium

Six O-type stars were observed continuously by the CoRoT satellite during a 34.3-day run. The unprecedented quality of the data allows us to detect even low-amplitude stellar pulsations in some of these stars (HD 46202 and the binaries HD 46149 and Plaskett's star). These cover both opacity-driven modes and solar-like stochastic oscillations, both of importance to the asteroseismological modelling of O stars. Additional effects can be seen in the CoRoT light curves, such as binarity and rotational modulation. Some of the hottest O-type stars (HD 46223, HD 46150 and HD 46966) are dominated by the presence of red-noise: we speculate that this is related to a sub-surface convection zone.

Reference: To be published in "Four decades of Research on Massive Stars", Astronomical Society of the Pacific. Eds. C. Robert, N. St-Louis and L. Drissen
Status: Conference proceedings