HST/GHRS Studies of $\zeta$ Aurigae.\\ I. GHRS Observations of the 1993 Eclipse
Session 18 -- Stellar Spectra: Individual Objects
Display presentation, Wednesday, January 12, 9:30-6:45, Salons I/II Room (Crystal Gateway)

## [18.08] HST/GHRS Studies of $\zeta$ Aurigae.\\ I. GHRS Observations of the 1993 Eclipse

Alexander Brown, Jeffrey L. Linsky, Philip D. Bennett, Graham M. Harper (JILA, U. of Colorado \& NIST), Robert Baade, Thomas Kirsch, Dieter Reimers (Hamburg University, Germany)

The eclipsing binary $\zeta$ Aurigae (K4 Ib + B5 V) was observed using the Goddard High Resolution Spectrograph (GHRS) on Hubble Space Telescope (HST) at five epochs immediately preceeding and one following the April 1993 eclipse of the the hot B-type secondary by the K supergiant primary. A combination of Echelle-B and medium resolution G160M spectra were obtained at phases 0.78, 0.948, 0.957, 0.972, 0.978 and 1.13. These observations sample the absorption of the hot star's photospheric spectrum by the extended intervening cool star atmosphere. The GHRS spectra are presented and the circumstances of the individual observations are described. Fundamental parameters of the binary system derived from these data are discussed. \\ This work is supported by HST grant GO-3626.01-91A to the University of Colorado.