THE WINDS OF HOT, CLOSE BINARIES .1. Y-CYGNI (HD-198846)

High-resolution IUE images of Y Cygni have been used to study the wind s from the stars of this close binary by means of the SEI method. Best average fits to wind-line profiles show that line formation extends t o more than a stellar radius above each photosphere. For each star, th e mass-loss rate is comparable to that of single stars of a similar ev olutionary stage. A second computer code that quantifies wind attentua tions and eclipses has been developed to account for the residual abso rbed flux not modelled by SEI. For this to be successful, it was neces sary to include a local enhancement in the opacity of the wind envelop e of one star. Application to the C IV absorption was more successful than to Si IV.