A Hard Look at the Colliding Winds in the gamma Velorum system

We propose to explore the orbital variability of the nearby WR+O binary, gammaVel. This system has been the subject of a recent optical variability campaignfor both spectroscopy and precision photometry with the BRITE nanosatellites.The Xray data will provide direct constraints on the shock physics andradiative braking processes that are present in the system. Unlike most othercollidingwinds binaries, we have a highquality visual orbit, a distanceaccurate to 7 pc, and a direct measurement of the luminosities of both stars. Assuch, the gamma Vel system will constrain how these processes work. Lastly,these observations will be made parallel to precision photometry from BRITE,allowing for a connection to be made between Xray and optical variability. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]