1998 Superoutburst of the Large-Amplitude SU UMa-Type Dwarf Nova WX Ceti

We observed the 1998 November superoutburst of WX Cet, a dwarf novaoriginally proposed as a WZ Sge-like system. The observation established thatWX Cet is an SU UMa-type dwarf nova with a mean superhump period of 0.05949(1)d, which is 2.1% longer than the reported orbital period. The lack of earlysuperhumps at the earliest stage of the superoutburst, the rapid development ofusual superhumps, and the possible rapid decay of late superhumps seem tosupport that WX Cet is a fairly normal large-amplitude SU UMa-type dwarf nova,rather than a WZ Sge-type dwarf nova with a number of peculiarities. However, aperiod increase of superhumps at a rate dot(P)/P = (+8.5+/-1.0) x 10^-5 wasobserved, which is one of the largest dot(P)/P ever observed in SU UMa-typedwarf novae. A linear decline of light, with a rate of 0.10 mag/d, was observedin the post-superoutburst stage. This may be an exemplification of the decay ofthe viscosity in the accretion disk after the termination of a superoutburst,mechanism of which is proposed to explain a variety of post-superoutburstphenomena in some SU UMa-type dwarf novae.Comment: 8 pages, 8 figures, accepted for publication in Publ. Astron. Soc. Japa