RAT J1953+1859: a dwarf nova discovered through high amplitude QPOs in
  quiescence
  We report the discovery of an accreting binary, RAT J1953+1859, made during
the RApid Temporal Survey (RATS) on the Isaac Newton Telescope. It showed high
amplitude (0.3 mag) quasi-periodic oscillations on a timescale of ~20 mins.
Further observations made using the Nordic Optical Telescope showed it to be ~4
mag brighter than in the discovery images. These photometric observations,
together with radial velocity data taken using the William Herschel Telescope,
point to an orbital period of ~90 mins. These data suggest that RAT J1953+1859
is a dwarf novae of the SU UMa type. What makes RAT J1953+1859 unusual is that
it is the first such system to be discovered as a result of high amplitude QPOs
during quiescence. This suggests that high-cadence wide-field surveys could be
another means to discover cataclysmic variables as a result of their short
period variability.
