In GLASS data taken of the MACSJ1149.6+2223 cluster (z=0.54) in November, we discovered the first strongly lensed supernova visible in multiple images. The supernova occurred in the spiral arm of a galaxy at redshift z=1.49 lensed by a foreground early-type cluster galaxy, whose gravitational potential forms four separate, strongly magnified images of the supernova. With the Frontier Fields SN team, we describe the exciting system in Kelly et al. 2014.
Our team is measuring the time delays and relative magnifications between the separate images of the evolving supernova, by comparing the phase and brightness of the multiple light curves. These delays and magnifications will place tight constraints on the cosmic expansion rate, as well as the distribution of luminous and dark matter in the galaxy lens and the cluster.