The Detection of a Repeating Structure in the Envelope of $\zeta$~Aurigae
Session 85 -- Binaries
Display presentation, Wednesday, 11, 1995, 9:20am - 6:30pm

## [85.21] The Detection of a Repeating Structure in the Envelope of $\zeta$~Aurigae

Graham M. Harper (JILA, University of Colorado), Philip D. Bennett (JILA, University of Colorado), Alex Brown (CASA, University of Colorado)

We report on the detection of a repeating structure in the envelope of the eclipsing binary $\zeta$~Aurigae (K4 Ib + B5~V). Two distinct absorption components are observed for many of the strong Fe~II lines in medium resolution spectra taken with the Hubble Space Telescope GHRS at ingress eclipse phases $\phi=0.943$ and $\phi=0.957$. At the ingress phase $\phi=0.780$ and the egress phase $\phi = 0.133$ the low velocity absorption component of the Fe~II is not observed. High resolution Echelle spectra reveal that the two absorption components have a similar complex structure, but with the high velocity component having a smaller column density. This evidence strongly suggests that the two absorption components have a common physical origin and that the envelope $\zeta$~Aurigae A \& B is highly structured.

We present simple models of the absorbing structures and compare the column densities with those derived from IUE spectra (Eaton) and those from the recent 2-D radiative transfer calculations of Kirsch \& Baade.