Abstract

We have found cyclic light variations with high amplitude during quiescence possibly reflecting the binary motion of the cataclysmic variable BR Lupi. With this hypothesis, an orbital frequency of 12.573 (1.91 hr) ± 0.071 cycles day -1 is derived. In addition, differential photometry obtained during the 1995 March superoutburst shows superhumps with amplitude 0.25 mag and frequency 12.171 (1.97 hr) ± 0.106 cycles day -1. H? emission line radial velocities measured during the decline of the superoutburst follow the orbital motion with half-amplitude 54 ± 16 km s -1. The mass function along with several empirical and theoretical constraints enabled us to estimate the primary mass M 1 = 1.0(1) M ?, the secondary mass M 2 = 0.146(1) M ?, and the inclination angle (50° < i < 65°).