Colliding Winds: A Spectropolarimetric Analysis of the Binary Star System WR 71
Determining the mass loss rate of stars is crucial in determining their eventual evolution. Wolf-Rayet binary stars are systems consisting of an evolved, massive Wolf-Rayet star and an O-type star, which produce high stellar winds that blow dust and gas around the system and ultimately meet at a shock region between the two stars. By studying how light is scattered in the winds after it is produced both by the stars themselves and the shock region, we can begin to constrain these systems. This technique is called polarimetry, and we obtained such data from the Southern African Large Telescope (SALT). I analyzed data pertaining to one of these binaries and developed a technique to better characterize the emission-line profiles of the system, which involves measuring how symmetric each profile is. Preliminary results indicate large differences between emission lines of different ionic species, as well as between emission lines of the same species as a function of the orbital motion of the system. Fully characterizing these line emission and scattering regions will help to constrain the geometry of the WR71 system and eventually understand its mass loss.