  We report the discovery of a new dwarf nova and our observations of its first
confirmed superoutburst during 2009 October. The outburst amplitude was 6
magnitudes. The main outburst lasted 17 days and was followed 4 days later by a
remarkable rebrightening. Superhumps were present during the main outburst,
which confirms that it belongs to the SU UMa family. Initially the mean
superhump period was Psh = 0.06965(17) d, but analysis of the O-C residuals
showed a dramatic evolution in Psh during the outburst. During the first
two-thirds of the plateau phase the period increased with dPsh/dt = +1.24(5) x
10-3. There was then an abrupt change following which the period decreased with
dPsh/dt = -1.01(9) x 10-3. The amplitude of the superhumps also varied, with a
maximum amplitude near the beginning of the outburst and a second maximum
corresponding to the discontinuity in Psh. Analysis of archival data showed
outbursts also occurred in October 2005, June 2006 and June 2007. Assuming that
the superoutbursts are periodic, we estimate that the outburst period is around
450 days.
