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Session 42 - Orfeus & STIS.
Display session, Wednesday, June 11
South Main Hall,
We present the first results from FUV observations of six Algol-type interacting binary stars obtained with the UC Berkeley spectrometer on the ORFEUS-SPAS II payload that was flown on STS-80 in November/December 1996. Spectra in the region 900-1220 Åat a resolution of 90 km s^-1 were obtained of AU Mon (B3Ve + F8III, P=11.11 d., \phi = 0.58), Z Vul (B3V + A2III, 2.46 d., 0.27), U CrB (B6V + F8III-IV, 3.45 d., 0.62), TX UMa (B8V + F2III-IV, 3.06 d.,0.43, 0.45), TT Hya (B9.5V + K0III-IV, 6.95 d., 0.63, 0.95, 0.19), and SX Cas (A6-disk + K3III, 36.57 d., 0.02). S/N ratios in the range 15-50 were achieved. The spectra of these interacting binary systems, including the emission lines from intermediately-ionized species observed in SX Cas during totality, will be discussed in detail. We will present evidence for the presence/absence of highly-ionized species such as O VI and bipolar flows, an intercomparison of the systems, and a comparison between the observations and the expectations from mass transfer models for these systems. We thank NASA for support of this mission and its data reduction.