UV and optical observations of variability in the WR+compact candidate HD 96548.

Abstract

The present IUE SWP high resolution spectra of the WR+ compact candidate HD 96548 exhibit significant variability in the P Cygni and emission line profiles. A reanalysis of previously published visible photometry in light of new data shows that all the photometry is periodic, with a period of 5.879 d or its one-day aliases at 0.855 and 1.204 d. The UV profile variations can only be explained by a compact companion if the X-rays modify the dynamics of the entire wind by decreasing radiative acceleration. Observed line profile changes are compatible with intrinsic stellar wind variations caused by fluctuations in the continuum radiative flux; stellar pulsation of some type is then required to explain the periodicity in the continuum variations.