Time-resolved optical studies and Doppler imaging of the eclipsing dwarf nova V893 Scorpii

We present time-resolved optical spectroscopic and photometric, observation s of the re-discovered dwarf nova V893 Sco. The orbital period of 0.(d)0761 0(3) derived from the radial velocity and equivalent width Variations of th e H alpha emission line is confirmed. The photometric light curves clearly show the eclipse of the accretion disk. A mass of the white dwarf similar t o0.5-0.6 M. is derived from the orbital amplitude K-1 = 86 +/- 11 km s(-1) and the eclipse constraint. The mass ratio is likely small enough to make V 893 Sco an SU UMa-type dwarf nova, though this object has shown only normal outbursts in its light curve. Time-resolved Doppler maps for the emission lines show two isolated Her emission regions, which are associated with a s trong hot spot and the irradiated secondary star.