An analysis of emission lines in the spectrum of PCygni

Using the coudé spectrograph of the NAO 2m telescope at the RhodopeMountains, Bulgaria, 9 spectra in the blue and 8 spectra in the red photographic region of P Cygni were obtained during 1990. By averaging the spectra in each set a S/N-ratio of about 45was achieved. Comparing the lists of identifications published by Beals (1950), de Groot (1969), Ozemre (1978), Stahl et al. (1993), Markova (1994) and Markova & Zamanov (1995), we conclude that the emission spectrum of P Cygni in our days is probably much richer and intensive than 60 years ago. A number of line parameters of the pure emission lines are measured. An estimate of the electron density and temperature in the region of [NII]-lines formation is obtained. Different velocity laws yielding similar density structures are discussed aiming to account for the results obtained on the basis of the [NII] lines. Possible mechanisms for the formation of the permitted pure emission-line spectrum are proposed.