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   PR #   128
   HD193793 (O4-5V + WC7) is the most luminous Wolf-Rayet binary know
   with L(x) = 10^34.6 erg/s (0.5 - 4 keV EXOSAT). GINGA detected a hard
   spectrum from 2 - 20 kewith an Fe emission line at 6.6 keV. The soft
   x-rays most likely originate in a shock-heated region where supersonic
   winds from each component collide. The x-rayspectra of WR systems are
   expected to depend on wind chemical abundances, whichmay be non-solar.
   High-res SIS spectra will provide data on wind chemistry thatcan be
   compared with extensive theoretical work (Stevens et al '92). SIS
   line-repower will be tested via a number of emission lines (C, N, O,
   Mg, Ne, Fe) originain the thin shocked plasma at energies 0.5 - 8 keV.
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