Photometric observations of the supernova 2009nr

TL;DR

This paper reports detailed photometric observations of supernova 2009nr, analyzing its light curves and properties, and suggests it likely resulted from a white dwarf merger, contributing to understanding luminous Type Ia supernovae.

Contribution

It provides the first detailed UBVRI photometry of SN 2009nr, characterizes its light curves, and proposes a white dwarf merger origin, expanding knowledge of supernova diversity.

Findings

SN 2009nr is similar to SN 1991T in light-curve shape and luminosity.

SN 2009nr exploded in the galaxy's halo, indicating an old progenitor population.

The supernova's properties support a white dwarf merger origin.

Abstract

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.