Confirmation of the SU UMa-Type Nature of the Suggested Intermediate Polar VZ Pyxidis

We observed VZ Pyx (=H0857-242), a suspected intermediate polar (IP), during a bright outburst in 1996 May. Time-resolved CCD photometry revealed superhumps with a period of 0.07576 (+/- 0.00003) d, confirming the SU UMa-type nature of the object. Unlike other intermediate polars, the superhump and outburst properties of VZ Pyx are quite similar to those of non-magnetic dwarf novae, suggesting a minor effect of global magnetism on the outburst mechanism of this system. If VZ Pyx is really proven to be an IP by future detection of X-ray pulses, this system might provide a unique opportunity to investigate what mechanisms regulate the accretion process and disk instabilities in magnetic dwarf novae.