IUE and Voyager Observations of the Unusual Cataclysmic Variable S193

Abstract

UV observations of S193 were obtained with Voyager and the IUE satellite during both high and low states of this unusual object. Voyager only detected the source during the high state, where the continuum looks similar to the novalike IX Vela and dwarf novae at outburst. The IUE spectra at the high state show deep absorption lines, but the line ratios are not typical of disk cataclysmic variables at outburst. They are most similar to V795 Her and the SW Sex star PG0859+415. At the low state, only CIV and MgII are in emission, while the deep absorptions at SiIII and NV persist. The spectra at this state are most similar to the intermediate polar candidate H0551-819. The UV observations of S193 provide further circumstantial evidence for the existence of a disk and a magnetic white dwarf in an intermediate polar system.