# Deja Vu All Over Again: The Reappearance of Supernova Refsdal Academic Article

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• Overview
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• Abstract In Hubble Space Telescope (HST) imaging taken on 2014 November 10, four images of supernova (SN)" Refsdal"(redshift z= 1.49) appeared in an Einstein-cross-like configuration (images S1–S4) around an early-type galaxy in the cluster MACS J1149. 5+ 2223 (z= 0.54). Almost all lens models of the cluster have predicted that the SN should reappear within a year in a second host-galaxy image created by the cluster's potential. In HST observations taken on 2015 December 11, we find a new source at the predicted position of the new image of SN Refsdal approximately $8^{\prime\prime}$ from the previous images S1–S4. This marks the first time the appearance of a SN at a particular time and location in the sky was successfully predicted in advance! We use these data and the light curve from the first four observed images of SN Refsdal to place constraints on the …