We report on detailed studies of the absorption line spectrum and spectroscopic orbit of the binary BN2.5Ib star HD 235679. We also give ao preliminary report on our study of the Hα emission line profiles from this perplexing system. Hipparcos and Tycho2 astrometric data allow us to place limits on the distance to the system. The lack of a measurable reflection effect in the Hipparcos photometry allows us to rule out the possibility that the massive invisible star is cool and fills its Roche lobe. Thus, by process of elimination, the invisible star must be hot or a black hole. The properties of the Hα profiles suggest that the invisible star is somewhat hotter, and has a stronger wind than HD235679.
We present preliminary results from a spectroscopic survey for absorption line profile variations among the O stars. Our data consist of more than 1000 high quality spectra of 46 bright O stars which were obtained with sufficient time resolution to sample variations with timescales of hours to days. Most spectral types and luminosity classes are represented. We find that about 31% of these stars exhibit photospheric variability which probably arises from organized velocity fields. The remaining stars are either constant (31% of the sample) or possess variability associated with their winds (43% of the sample, including 2 of the photospheric variables). We present examples illustrating each of these classes of behaviour, and discuss preliminary implications and future
directions of this work.