Observatoire de la Côte d'Azur, Département FRESNEL, CNRS UMR 6528, 2130, route de l'Observatoire, Caussols, 06460 St Vallier de Thiey, France

We investigate the shape of the envelope around B[e] supergiant stars using a model developed by Stee & Araùjo (1994) for Be stars. We obtain mass loss rates between 5.5×10^-7 and 6.2×10^-6 M yr^-1 depending on mass flux variation from polar to equatorial regions. We find that winds from B[e] stars can be so dense that they become optically thick in the continuum, masking the photosphere of the central star. For mass loss rates larger than 10^-5 M yr^-1 it is not possible to see the stellar photosphere even for pole-on B[e] stars. Using a two-component wind model driven by optically thin lines in the equatorial regions and optically thick lines in the polar regions, we obtain a relation between the geometry of the envelope and the total mass loss. We also put limits on the inclination angle (i) beyond which the stellar photosphere is masked. Finally, this study seems to discard "wind-compressed disks" (WCD) models as a possible scenario for B[e] supergiant envelopes.

1998, A&A, 336, 980