BROAD-BAND X-RAY TELESCOPE SPECTROSCOPY OF ZETA-PUPPIS

The Broad-Band X-Ray Telescope (BBXRT) obtained moderate-resolution (approximately 90 eV) X-ray spectra of the 04 f star zeta Pup during the STS 35/Astro 1 mission in 1990 December. Despite the shortness of the observation (600 s), the data show a surprising amount of detail. We report the detection of an 0 absorption edge produced by ionized overlying wind material and K-shell line emission from Mg produced by a thermal plasma of temperature near 6 x 10(6) K. The data are used to place constraints on the location, temperature, and amount of the X-ray-emitting gas, as well as the abundance and ionization of the wind material.