Modeling Hydrogen-Rich Wolf-Rayet Stars in M33

Abstract

We present the results of a spectral variability study of two very luminous stars in the M33 galaxy -LBV V532 and late WN star (possibly, dormant LBV) FSZ35. We studied spectral variability of V532, derived its atmosphere parameters and showed that the bolometric luminosity varies between the two states by a factor of ∼1.5. Using the non-LTE radiative transfer code CMFGEN, we determined wind parameters for both objects. Since both stars are located at distances of about 100 pc from the nearest association, we supposed that they may be massive runaway stars with velocities of the order 100km s −1 .