Abstract

Fundamental Parameters of 4 Massive Eclipsing Binaries in Westerlund 1

Alceste Bonanos (National Observatory of Athens, Greece)

E. Koumpia (National Observatory of Athens)

We present fundamental parameters of 4 massive eclipsing binaries in the young massive cluster Westerlund 1. The goal is to measure accurate masses and radii of their component stars, which provide much needed constraints for evolutionary models of massive stars. Accurate parameters can further be used to determine a dynamical lower limit for the magnetar progenitor and to obtain an independent distance to the cluster. Our results confirm and extend the evidence for a high mass for the progenitor of the magnetar.

AZB acknowledges research and travel support from the European Commission Framework Program Seven under the Marie Curie International Reintegration Grant PIRG04-GA-2008-239335.