Wolf-Rayet stars

Optical spectrophotometry and spectropolarimetry are presented for three WC9 stars. It is concluded that each of these stars is a binary system on the basis of the existence of excess continuum flux that perceptibly dilutes the emission lines. The extreme WC9 star Ve 2-45 suffers 4.7 +- 1 mag of circumstellar extinction in a dust shell. Two distinct components of polarization can be recognized: a wavelength-independent component attributed to electron scattering, and a steep component in the blue consistent with lambda-4 Rayleigh scattering. A gas envelope with plausible parameters can produce the former polarization but the latter requires either molecular or small solid entities, perhaps the condensation nuclei of the hot dust grains seen at infrared wavelengths. (author)