Twins with a tweak: direct test of colliding wind physics

Massive stars eject powerful stellar winds, which collide in massive binaries.By probing such windwind collisions, direct insight into the wind properties isprovided. However, this derivation requires a good modelling, which needs to bethoroughly ascertained. To this aim, we propose a natural controlledexperiment.. by observing collidingwind binaries which differ by one parameterat a time.