Abstract

Time resolved H? spectroscopy and differential photometry at the U, B bands, reveal an orbital period of 1 h.884 ± 0 h.005 and a K radial velocity semiamplitude of 49 ± 6 km s -1. The dynamical solution and spectroscopic measures indicate a mass ratio M 2/M 1 = 0.115 ± 0.005, a primary mass M 1 = 1.23 ± 0.23 M ?, a secondary mass M 2 = 0.15 ± 0.03 M ? and an inclination angle i = 59° ± 6°. Doppler imaging reveals a line emissivity decreasing with radius as r -1.4. Smooth 0 m.11 semiamplitude periodic oscillations at U and B bands, H? V/R variations and equivalent width oscillations up to 15% of the mean value, could be due to a hotspot located in the stream-disk impact region. This picture is supported by the H? Doppler tomogram.