ULTRAVIOLET OBSERVATIONS OF WZ-SAGITTAE IN OUTBURST

We describe low and high resolution ultraviolet spectroscopic observations of the recurrent nova WZ Sge obtained during its 1978 December outburst. A large number of low resolution images were obtained on December 14 and 24. On December 14 the continuum shape and intensity and C IV emission line intensity were highly variable, whereas there was little variation on December 24. The continuum on both days may be fitted by a power law or an optically thick accretion disc spectrum. The average continuum on December 24 is fainter but of steeper slope than the average on December 14. Spectral features due to CIV, Nv, SiIV, SiII, 01, C II and possibly He II are identified in the low resolution data. No C III] A1909 emission is present. The few high resolution images confirm the features found at low resolution and cover a wider time span. The distance to WZ Sge is estimated by two methods to be of order 100 pc. © Royal Astronomical Society • Provided by the NASA Astrophysics Data System.