Institution(s): 1. European Space Agency
Mass-loss rates in massive stars remain an open question, which X-ray observations can help resolve.
HD 150136 is a multiple system containing the nearest star classified as an O3. The variability unveiled by its X-ray lightcurve could be due to the stellar winds colliding.
For the first time, an X-ray observation of HD 150136 covering its entire orbital period of 2.7 days was recently performed: our main purpose is to definitively identify the origin of the X-ray variability, and to constrain the physical parameters of the stars.
We will discuss mass-loss rates derived from our detailed X-ray study of HD 150136.