Evolutionary models of the optical component of the LMC X-1/Star 32 binary system

Calculations carried out to model the evolution of Star 32 under different assumptions about the stellar wind mass-loss rate provide robust limits on the present mass of the star. The obtained range is 31 to 35.5 Msun, which is in very good agreement with the orbital solution of Orosz et al., namely 28.3 to 35.3 Msun. The initial mass of Star 32 had to be in the range 35 to 40 Msun and the present age of the system is 3.7 to 4.0 Myr.