Using polarization to study the winds of massive stars

The topic of wind-clumping has been the subject of much activity in recent years, due to the impact that it can have on derived mass-loss rates. Here we present an alternative method of investigating wind-clumping, that of polarimetry. We present simulations of the polarization produced by a clumpy wind, and argue that the observations may be reproduced just by statistical deviations from spherical symmetry when the outflow is only slightly fragmented. Here, the polarization scales with Ṁ , which is consistent with observations of LBVs, WRs and O supergiants. Finally, we find clumping factors in the inner 2R⋆ of ∼ 2− 3, and speculate as to the clumping stratification of hot stars.