He II Emission in the Wolf–Rayet Binary Star, CQ Cephei

Abstract

THE origin of the emission lines in Wolf–Rayet stars is not entirely understood. There is supporting evidence that the emission arises in either an envelope large relative to the central star or in an envelope compactly surrounding the central star. It is obvious that if a light curve of an eclipsing binary in which one component were a Wolf–Rayet star could be obtained from a single emission line, one would have valuable data regarding the position of the emitting atoms. For if the emitting atoms were in an envelope large relative to the central star, there would be little change in the intensity of the emission as the Wolf–Rayet star was eclipsed by its companion. If the emission originated in an envelope close to the parent star, then an eclipse of the emission would be expected. An attempt was made to observe the light curve of CQ Cephei in He II 4686 photographically during September 1947. However, the results were not conclusive, although it was suspected from visual inspection of earlier spectrograms that the emission was not constant¹.