Abstract

We present time-resolved optical spectroscopic and photometric, observations of the re-discovered dwarf nova V893 Sco. The orbital period of 0.(d)07610(3) derived from the radial velocity and equivalent width Variations of the 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 to0.5-0.6 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 V893 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 strong hot spot and the irradiated secondary star.