Dwarf Nova-Like Outburst of Short-Period Intermediate Polar HT Camelopardalis

Our time-series photometric observations of a short outburst of HT Cam in 2001 strongly suggest that disk instabilities occurred during the outburst. HT Cam is a cataclysmic variable identified as the optical counterpart of the hard X-ray source RX J0757.0+6306, discovered during the ROSAT All-Sky Survey. Tovmassian et al. (1998) suggested that this object is an intermediate polar with a shortest orbital period of 80.92min and a spin period of 8.52min. However, the existence of dwarf nova-like outbursts and the short orbital period allowed an alternative interpretation that it may be an SU UMa-type dwarf nova or WZ Sge-type stars (Tovmassian et al. 1998).