ECLIPSING BINARIES IN THE MAGELLANIC CLOUDS .2. ABSOLUTE DIMENSIONS AND DISTANCE MODULUS FOR HV-5936 IN THE LARGE MAGELLANIC CLOUD

Absolute dimensions and the distance modulus have been established for the early-type eclipsing binary HV 5936 in the LMC. Analyses of new radial velocities, reported here, and CCD light curves published by Jensen, Clausen and Gimenez yield masses of 7.2 +/- 0.9 and 3.3 +/- 0.5 M. for the primary and secondary components respectively. The corresponding radii are 4.6 +/- 0.3 and 5.7 +/- 0.3 R. with the cooler star filling its Roche lobe. More radial-velocity data are needed for definitive orbital parameters of HV 5936. The system appears to be similar to HV 2226 in the SMC in the sense of being a post-mass-transfer system, but due to case AB or B evolution rather than case A. A distance modulus of (m(V) - M(V))(0) = 18.1 +/- 0.3 mag is derived, which marginally favours the 'short' distance to the LMC noted by Westerlund of (m(V) - M(V))(0) = 18.2mag; the range of (m(V) - M(V))(0) values reported in Westerlund's review is 17.9-18.7mag. As for HV2226 in the SMC, the accuracy of the estimate of (m(V) - M(V))(0) is limited by uncertainties of approximate to 2000 K in the effective temperatures, and by the limited radial-velocity data.