THE IUE MEGA CAMPAIGN - WIND VARIABILITY AND ROTATION IN EARLY-TYPE STARS

Wind variability in OB stars may be ubiquitous, and a connection betwe en projected stellar rotation velocity and wind activity is well estab lished. However, the origin of this connection is unknown. To probe th e nature of the rotation connection, several of the attendees at the w orkshop on Instability and Variability of Hot-Star Winds drafted an IU E observing proposal. The goal of this program was to follow three sta rs for several rotations to determine whether the rotation connection is correlative or causal. The stars selected for monitoring all have r otation periods less than or equal to 5 days. They were HD 50896 (WN5) , HD 64760 (B0.5 Ib), and HD 66811 [zeta Pup; O4 If(n)]. During 16 day s of nearly continuous observations in 1995 January (dubbed the ''MEGA '' campaign), 444 high-dispersion IUE spectra of these stars were obta ined. This Letter presents an overview of the results of the MEGA camp aign and provides an introduction to the three following Letters, whic h discuss the results for each star.