Atmospheric Parameters and Chemical Abundances of Pulsating β Cephei Stars in Open Clusters

β Cephei stars are massive, non-supergiant, intrinsic variables. Theoretical investigations indicate that their pulsation mechanism strongly depends on the abundance of heavy elements. Until now, hundreds of these B-type variables were discovered photometrically, but only for a small sample spectroscopic data are available. We present the results of the investigation of high-resolution and high signal-to-noise spectra of β Cephei stars in the young open clusters. We use TLUSTY and SYNTHE codes to calculate models of the atmospheres and synthetic spectra, and spectrum synthesis method to analyse the data. For all stars, we determine effective temperatures, surface gravities, projected rotational velocities, micro- and macroturbulences, and metallicities.