Mass-loss of hot stars studied with spectro-polarimetric interferometry (SPIN)

Abstract

We describe the prospective work undertaken on an interferometric technique using polarimetry called SPIN (Spectro-Polarimetric INterferometry). The polarizing phenomena described in this work have to be taken into account by any stellar interferometer in order to control the fringe signal. Adding a polarimetric device at their combined focus represents no technical difficulty. The use of SPIN can extend interferometry by an important complementary tool for locating and quantizing the mass loss from early type stars since these stars are subject to strong Thomson scattering in their vicinity. As an illustration of the potential of SPIN, we present the results of Monte-Carlo simulations showing the expected signal for realistic hot star environment. Radiative winds ranging from A supergiants to earliest O stars are considered. In particular, the results show the strong expected signal from spherical winds for which no detection of polarization is achievable by classical technics.