Curious Variables Experiment (CURVE). CCD Photometry of Dwarf Nova V660 Herculis

We report extensive photometry of the dwarf nova V660 Her. During our campaign, lasting from August 2003 to November 2004, we recorded one bright eruption which turned out to be a superoutburst lasting about 15 days and having amplitude of ≈4.5 mag. Clear superhumps with a mean period of Psh=0.080924(18) days (116.53±0.03 min) were present during all nights of the superoutburst. The period of the superhumps was not stable and in the interval covered by our observations it decreased with a rate of P/Psh=-4.0(1.4)×10-5. Based on our data and the known orbital period of the binary we calculate the period excess of 3.4±0.1%, which is typical for an SU UMa star at this orbital period. This value indicates that the mass ratio of the system is q=0.154