4-COLOR PHOTOMETRY OF ECLIPSING BINARIES .35. LIGHT CURVES OF GG LUPI - YOUNG METAL-DEFICIENT B-STARS

This paper presents the first photoelectric light curves (uvby) of the bright southern detached double lined eclipsing binary GG Lupi (HR5687, B7 V + B9 V, p = 1.85d) consisting of two main sequence stars (4.1 M. and 2.5 M.) close to the ZAMS. The orbit of GG Lup is eccentric (e = 0.150) and shows apsidal motion (U = 101 yr). The light curves, which contain 1035 observations in each colour, were collected during March 1985. Observations from 1987-91 for 10 additional times of minima are also given. Accurate masses and radii (almost-equal-to 1%) of the components have been established from an analysis of the light curves and of new radial velocity curves. A detailed study of GG Lup is published separately (Andersen et al. 1993).