Photometric observations of the supernova 2009nr
  We present the results of our UBVRI CCD photometry for the second brightest supernova of 2009, SN 2009nr, discovered during a sky survey with the telescopes of the MASTER robotic network. Its light and color curves and bolometric light curves have been constructed. The light-curve parameters and the maximum luminosity have been determined. SN 2009nr is shown to be similar in light-curve shape and maximum luminosity to SN 1991T, which is the prototype of the class of supernovae Ia with an enhanced luminosity. SN 2009nr exploded far from the center of the spiral galaxy UGC 8255 and most likely belongs to its old halo population. We hypothesize that this explosion is a consequence of the merger of white dwarfs. 
D. Yu. Tsvetkov, P. V. Balanutsa, V. M. Lipunov, I. M. Volkov, O. A.   Tuchin, I. P. Kudelina, M. V. Pruzhinskaya, E. S. Gor...
astro-ph.SR