WINDS OF LUMINOUS OB STARS

We review the historical development of observations of mass loss from hot, luminous stars, and sketch the physical principles underlying th e theory of radiatively-driven stellar winds. The theory makes predict ions which are shown to be in general accord with the data. We summari ze recent results, primarily from the IUE satellite, which demonstrate the importance of time-dependent phenomena in hot-star outflows, and which, in particular, point to effects related to rotational modulatio n.