After the discovery of the supernova, astronomers predicted that they would be able to see it again in about one year, after the four images had faded away. This is because the initially observed four-image pattern was only one component of the lensing display. The supernova may also have appeared as a single image some 40–50 years ago elsewhere in the cluster field. (with the exact date being uncertain by approximately one month which is the interval between two consecutive Hubble observations), in excellent agreement with the blind model predictions made before the reappearance was observed. The time delay between the original quadruplet observed in 2014 and the latest appearance of the supernova in 2015 was used to infer the value of the
Hubble constant. This is the first time this technique, originally suggested by Refsdal, has been applied to supernovae. Using measurements from SN Refsdal and galaxy cluster lens models, astronomers found that the Hubble constant has value H0 = km s−1 Mpc−1. == Other multiply-lensed supernova ==