Session 103 - Cool Stars.
Display session, Thursday, January 18
North Banquet Hall, Convention Center

## [103.05] AB Dor in '94

F. M. Walter (SUNY), A. Collier-Cameron (St. Andrews), N. Suntzeff (CTIO), M. Kürster (MPE), O. Vilhu (U. Helsinki), B. Slee (ATNF), Ghrs, M. teams

We undertook an extensive multiwavelength campaign to investigate the rapidly rotating ZAMS star AB Doradus (HD36705) in November 1994. The campaign included 3 nights of Doppler imaging spectroscopy from CTIO, 14 hours of continuous observations of chromospheric and transition region lines from the HST/GHRS plus another 5 hours of C IV flare monitoring observations, 5 days of continuous observations with the EUVE, simultaneous ROSAT HRI observations, as well as ground-based optical photometry and radio observations. We will provide an overview of rationale for the campaign, as well as of the detailed results. We will present the Doppler images and the dynamic H\alpha chromospheric map. We observed the ubiquitous extended H\alpha prominences'' in Mg II, and show that they contain gas at temperatures of 10^5K. We will discuss the lack of evidence for X-ray absorption at the time of H\alpha absorption dips, and its implications for the coronal structure. We observed 11 discrete flares, many at more than one wavelength, and demonstrate that R137B is not the source of the flares. We will discuss the flare timings at various frequencies.

These data allow us to build up a three dimensional picture of the outer atmosphere of a very unsolar-like active star.