SIMBAD references

The IUE archive offers a series of far UV spectra of ultra-short period dwarf nova WZ Sge over a long time baseline and hence the opportunity to monitor the ongoing accretion, the cooling of the white dwarf and temporal variations in the line spectra. We have carried out a quantitative analysis of these spectra including model atmosphere simulations. We find an indicated cooling of the white dwarf by 5140 K from 20510 K to 15370 K with a thermal e-folding time of 690 days. This cooling rate is well represented by heating of the white dwarf by accretion of matter with angular momentum during the December 1978 outburst followed by subsequent cooling. We find that the abundance of carbon in the white dwarf photosphere is elevated above solar. This finding is consistent with the results of recent HST observations. We find marginal evidence that the C abundance was 6x solar, close to the outburst and 2x solar in the most recent spectra obtained 13.7 years later.