SUPERHUMPS IN CATACLYSMIC BINARIES - XIV - V592-CASSIOPEIAE

We report a spectroscopic and photometric study of the novalike variab le V592 Cassiopeiae (=LS I 55 degrees 8). The spectrum is that of a ty pical UX UMa-type star, with weak, narrow Balmer emission superposed o n broad absorption. The 0.1-2.2 mu m flux distribution also looks fair ly normal, suggesting disk accretion at similar to 10(-8) M-. yr(-1) a nd a distance of 330 pc. The emission lines move with P = 0.115063(1) days, which is presumably the underlying orbital period of the binary. Photometry reveals a different period, namely, 0.12228(1) days. The p resence of this wave in a short-period cataclysmic variable, and the v alue of the period excess at 6.3%, suggests identification as a ''perm anent superhump.'' After subtraction of this large signal, the residua l time series appears to contain a weak feature at 0.11193(5) days. Th e star evidently shows positive and negative superhumps simultaneously . Its binary period puts it among a modest number of nonmagnetic catac lysmic variables occupying the 2-3 hr period ''gap.''.