Search for colliding stellar winds in Plaskett's star (HD 47129)

High dispersion spectra of Plaskett's star (HD 47129) were obtained with the short wavelength spectrograph on IUE at five phases of the binary cycle. The unsaturated wind profiles, particularly those of Si IV lambda 1400, show complex phase dependent structure. Two interpretations for the structure are suggested, neither of which is entirely satisfactory: (1) the structure is a consequence of directed streams, and (2) the structure is a consequence of colliding winds from the primary and secondary.