1995PASP..107.1055H

We report photometry of the dwarf nova CY Ursae Majoris during its 1995 superoutburst. A large-amplitude "superhump" at P = 0.07210 ± 0.00003 d was observed; the period decreased with P = -6 x 10^-5 over the 12 days of observation. The properties of the superhump appeared normal for SU UMa stars. But the frequencies of high harmonics were slightly blue-shifted from exact integer multiples of the fundamental, an effect which is unexplained but may require invoking differential precesion of the accretion disk.