SOFT-X-RAY EMISSION OF VY SCULPTORIS STARS DURING OPTICAL HIGH STATE

I have collected all available ROSAT observations of VY Sd stars inclu ding those during the all-sky survey to investigate the presence, stre ngth and spectrum of soft X-ray emission (0.1-2.4 keV) of this group o f nova-like variables. A total of 9 out of the 14 VY Sd stars are dete cted with ROSAT, mostly during optical high states. Interestingly, all detections during the optical high state have very similar X-ray spec tral characteristics. I find that a simple blackbody model gives a rea sonably good fit in all cases, with temperatures falling in the narrow range between 0.25-0.5 keV. Possible emission mechanisms are discusse d.