File:Galaxy Cluster MACS J1149.6+2223 and Supernova Refsdal.jpg

English: Astronomers using the Hubble Space Telescope to image massive galaxy cluster MACS J1149.6+2223 found a unique phenomenon: a distant supernova split into four images. The multiple images of the exploding star, named Supernova Refsdal, are caused by the powerful gravity of a foreground elliptical galaxy embedded in this massive cluster of galaxies in an effect known as "gravitational lensing."

First predicted by Albert Einstein, this effect is similar to a glass lens bending light to magnify and distort the image of an object behind it. Here, the gravity from both the elliptical galaxy and the galaxy cluster distorts and magnifies the light from the supernova behind them. The multiple images of the supernova are arranged around the elliptical galaxy in a cross-shaped pattern called an Einstein Cross, a name originally given to a particular multiple-imaged quasar, the bright core of an active galaxy.

The elliptical galaxy and its cluster, MACS J1149.6+2223, are 5 billion light-years from Earth. The supernova behind it is 9.3 billion light-years away.

For a close-up of the gravitationally lensed supernova, see: hubblesite.org/image/3496/news_release/2015-08

For more information, visit: hubblesite.org/news_release/news/2015-08

Credit: 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. Postman (STScI) and the CLASH team; and Z. Levay (STScI)