Recent spectral variation of the peculiar nova-like object PU Vulpeculae.

The spectroscopic evolution of PU Vul during the period from November 1986 to June 1988 is characterized on the basis of medium-dispersion 380-770-nm spectroscopy, CCD spectrophotometry, and photographic photometry obtained at Asiago Observatory. A spectral-density plot and a table of emission-line identifications are provided, and it is shown that the number of emission lines began to increase in about September 1987, when the light maximum faded (although more slowly than in 1980). Lines identified include those of H I, Fe II, Mg II, Si II, He I, forbidden Fe II and S II, Cr II, Ti II, and forbidden N II (575.5 nm). The Balmer emission lines extended to at least H(15) (371.2 nm), and the strongest lines had faint broad wings of FWZI about 2600 km/sec.