Ultraviolet photometry from the Orbiting Astronomical Observatory. X. Nova FH Serpentis 1970.

Results of ultraviolet filter photometry between 1430 and 4250 A and low-resolution spectral scans in the wavelength region A obtained with the Wisconsin package on the 0A0-A2 are reported for Nova FR Serpentis 1970. The observations were made over an interval of 53 days commencing at about the time of maximum visible light. Photometry measurements show the nova became progressively bluer during the early decline of the visual light curve; near maximum no signal was detectable shortward of 2460 A but 45 days later measurements were obtained at all wavelengths. The photometry data are corrected for extinction by estimating E(B - V) 0.8 and applying a representative ultraviolet extinction curve. With this correction the wavelength of maximum emission moves from longward of 5000 A at visual maximum to shortward of 2000 A by the end of the observations. The total flux as estimated from the corrected photometry and a V light curve remains constant to within a factor of 2; based on an estimated distance of 650 pc, the total measured optical luminosity is at least 3 x 10 ergs and the corresponding average luminosity about 2 x 10 L0. Spectral scans with a resolution of 20 A confirm the conclusions drawn from the photometry. The observed spectrum is dominated by emission from Mg II A2800 and by what are probably emission complexes due to Fe II. Subject headings: novae - spectrophotometry - stars, individual - ultraviolet