Credit: Credits: Illustration: NASA, ESA, A. Fields (STScI), and J. DePasquale (STScI). Science: NASA, ESA, and S. Rodney (JHU) and the FrontierSN team; T. Treu (UCLA), P. Kelly (UC Berkeley), and the GLASS team; J. Lotz (STScI) and the Frontier Fields team; M. P
This illustration, using Hubble Space Telescope images of Supernova Refsdal, shows how the gravity of massive galaxy cluster MACS J1149.6+2223 bends and focuses the light from the supernova behind it, resulting in multiple images of the exploding star. The upper graphic shows that when the star explodes, its light travels through space and encounters the foreground galaxy cluster. The light paths are bent by the cluster’s gravity and redirected onto new paths, several of which are pointed at Earth. Astronomers, therefore, see multiple images of the exploding star, each one corresponding to one of those altered light paths. Each image takes a different route through the cluster and arrives at a different time. In the lower graphic, the redirected light passes through a giant elliptical galaxy within the cluster. This galaxy adds another layer of lensing.