Abstract

We have established that the cataclysmic variable TU Crateris is an SU UMa star. Superhumps were observed after 3 days of the 1998 March-April supermaximum, repeating with a mean period of P s =0 d.08535(5). Timings of superhump maxima revealed a period decrease of ? = 7.2 × 10 -5. Based on an empirical relationship, we estimated an orbital period of 0 d.0810(25), just in the lower limit of the reported quiescence photometric period. H? emission lines during quiescence vary with the orbital period with radial velocity half amplitude of 70 ± 19 km s -1, evidencing a hotspot located in from of the standard position.