The variable H-alf P CYG profile of alf Cam : 09.5 Ia.

Observations of the Hα region of α Cam were obtained during 4 months in the winter of 1979 using modern electronic detectors on the two coudé spectrographs at McDonald Observatory. The P Cygni type emission profile at Hα is flanked by extensive, symmetric, nonvariable wings, which can be attributed to the effect of electron scattering in the emitting region. The low-velocity region of the emission core is highly variable, with changes being evident on a time scale of 6 hours to 1 day. The recurrence of similar profiles at multiples of the estimated rotation period suggests that the rotation of an inhomogeneous expanding envelope contributes to the observed variability. A weak, photo spheric absorption line of ionized helium shows no evidence of variability.