Discovery of thirteen novae candidates in M87

We have made thirteen positive identifications of near-ultraviolet (NUV) transient sources in the giant elliptical galaxy M87 using the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST). We give a representative sample of the light curves that we derive for these transients, and based on their characteristics we identify them as classical novae candidates. We obtain a hard lower limit for the nova rate in M87 of 64 novae per year. Our results suggest an enhancement on the frequency of nova events towards the nucleus of the galaxy. No correlation is found with either jet activity or the position of present day globular clusters.