V1016 cygni: spectral observations 1969-1973

Spectroscopic observations of V1016 Cygni made between 1969 and 1973 are presented. Identifications and log intensities are given for about 243 (120 newly reported) emission lines. The general appearance of the strong lines is about the same, implying that the conditions in the emitting regions have changed little. Parts of the nebula are slightly more ionized and less dense, as is evidenced by the appearance or strengthening of lines of [Ne iv], [Ne v], [Ar iv], [Ar v], [Fe III], [Fe iv], and [Fe vi]. The permitted iron lines have faded completely. The electron density remains at l0 -l0 cm 3, as is evidenced by the continued strength of [0 iii] A4363 and weakness of [0 n] AA3726 and 3729. The detection of 16 or more weak emission lines of Al H is reported. The emitting region is complex and nonsymmetrical. The maintenance of high density in an expanding region (at 34 km s -1) implies a continued outflow of material from the star. The violet wing of the emission lines is evidence for such a flow at 103 km s1. A model of the system is presented, explaining the radio, optical, and infrared components, in terms of a disk population object located 2400 pc away, which is in the process of becotning a planetary nebula. Subject headings: line identifications - mass loss - planetary nebulae - stars, individual