The Luminous Erupting Dwarf Nova CV1 in the Dense Globular Cluster M15
  Despite decades-old predictions of the expected presence of dozens of cataclysmic variables in the cores of globular clusters, the number of irrefutable, out-bursting candidates is still barely a handful. Using multi-wavelength, multi-epoch HST images we have produced outburst and quiescence light curves for the recently discovered large amplitude variable CV1 in the core of the post core-collapse globular cluster M15. The light curves and blue colors show that the object is a bona fide dwarf nova, with absolute magnitude at maximum light rivaling that of the most luminous known dwarf novae. 
Michael M. Shara (1), Sasha Hinkley (1), David R. Zurek (1), Christian   Knigge (2) ((1) Dept. of Astrophysics, AMNH (2) Dep...