ABSOLUTE DIMENSIONS AND MASSES OF SW-CANIS-MAJORIS

SW CMa (BD -22 degrees 1712, HD 54520) is a detached double-lined ecli psing binary with a very eccentric (e=0.3179) orbit and a long orbital period(10.09 days). New photometric and spectroscopic data have been obtained and analyzed. The results indicate that the binary consists o f a pair of A5 main sequence stars with an age of about 700 million ye ars, which puts the pair near the upper boundary of the main sequence band. The measured rate of apsidal motion due to relativistic and Newt onian causes is poorly determined by the available data, but is consis tent with the theoretically predicted rate (U=14000 years). (C) 1997 A merican Astronomical Society.