The Luminous Erupting Dwarf Nova CV 1 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, outbursting candidates is still barely a handful. Using multiwavelength, multiepoch Hubble Space Telescope images, we have produced outburst and quiescence light curves for the recently discovered large-amplitude variable CV 1 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.