Kholtygin A., Brown J., Fabrika S., Surkov A.
Magnetic field connected fast line profile variability in spectra of bright O supergiants
Magnetic stars, Proc. of the Intern. Conference, held in the Special Astrophysical Observatory of the Russian AS, August 27-31, 2003, Eds.: Yu. Glagolevskij, D. Kudryavtsev, I. Romanyuk, Nizhnij Arkhyz, p. 250-258. (2004)

Results of a study of fast line profile variability (lpv) in spectra of selected bright O-stars are reported. A regular component of {\em lpv} in spectra of the star lambda Ori A with estimated period P = 3d have been detected. We suppose that the formation of long time-scale regular components of {\em lpv} can be explained in the framework of the magnetically confined wind-shock (MCWS) model of Babel & Montmerle (1997a). In the context of testing the MCWS model a program of searching for weak magnetic fields in bright O and early B stars is outlined. The possibility to measure weak longitudinal magnetic fields B = 100 G is demonstrated.