Constraints on Wind Structure from the Infrared and Radio Continuum of Hot Stars

For 18 galactic hot stars (spectral type O-B3), we compare continuum observations gathered from the literature with the predictions of a NLTE model of a smooth wind. We find that for stars which have unambiguous observations at wavelengths beyond ~ 20 μm, a smooth wind model systematically underestimates the observed emission. We take this to be a confirmation of the presence of considerable structure in the stellar wind.