Polarization Variability Due to Clumps in the Winds of Wolf-Rayet Stars

Wolf-Rayet (WR) stars are understood to have clumpy winds [1]. Robert et al. [2] found a statistical relation between the variations of the polarization and the scattering light intensity, R = σ p/σ phot ≈ 0.05. To explain this result, we propose a model in which clumps are ejected from the surface of WR stars uniformly in space with a Gaussian time interval distribution. According to the observed R along with the subpeaks on the emission lines of WR stars, we can obtain the parameters of the velocity law index β, and of the clump ejection rate in a flow time N. Also, the fraction η of the total mass loss rate contained in the clumps can be found from the observed polarization