ORBITAL VARIABILITY IN THE WIND OF THE MASSIVE X-RAY BINARY HD 153919/4U 1700-37

Forty high-dispersion IUE spectra of HD 153919, the Of-type primary in the 4U 1700-37 X-ray binary system, have been examined for evidence of orbital profile variability associated with the Hatchett-McCray effect. Although the effect is negligible in the resonance lines of C IV, Si IV, and N V, some subordinate lines show clear orbital changes. The variability in the absorption profile of N IV λ1718, in particular, is shown to be in agreement with model calculations. The interstellar spectrum is studied, and highly ionized species are shown to be capable of being maintained by the primary's radiation field alone.