August 7-10, 2017


UW CMa: An Enigmatic Massive Contact Binary

Herbert Pablo (AAVSO)

Anthony Moffat University of Montreal Noel Richardson University of Toledo

Massive stars have a high multiplicity fraction which often leads to mergers. As many single massive stars are a result of this evolutionary channel it is important to understand how the stars came to be. While it is difficult to know which objects will merge, contact systems are likely candidates. UW CMa is not only a contact system, but a rarity composed of two supergiants. Using two-color BRITE photometry as well as radial velocities taken by SASER we attempt a binary model of this system. Moreover, we will discuss the unique asymmetries present in the light curve and what these could mean to our understanding of massive contact systems.

Mode of presentation need to be confirmed by the SOC