Supernova captured in quadruple comes back for an encore

BACK FOR MORE Supernova Refsdal made a dazzling quadruple display (left, red arrows) in late 2014 and was predicted to show up again in a different part of a galaxy cluster (left, circle). Right on cue, it made its predicted fifth appearance in December (bottom right, circle).

NASA, ESA and P. Kelly/Univ. of California Berkeley

By Christopher Crockett

January 5, 2016 at 7:33 pm

KISSIMMEE, Fla. — A scene-stealing supernova is back for an encore. After last year’s quadruple replay, supernova Refsdal has shown up a fifth time, thanks to the many meandering paths its light takes through an intervening galaxy cluster. The most recent appearance showed up in December in images taken by the Hubble Space Telescope. Astronomer Patrick Kelly, of the University of California at Berkeley, reported the discovery January 5 at a meeting of the American Astronomical Society.

Gravity from the cluster warps light from background galaxies and creates three images of Refsdal’s galactic home. One of those images lands on another galaxy within the cluster, whose gravity created the 2014 quadruple supernova display. Shortly after that quartet, several researchers predicted that Refsdal would show up once more in late 2015. Almost on schedule, the supernova appeared in a different image of the host galaxy closer to the center of the cluster.

For a supernova that keeps on giving, the December event might be its last, says Kelly, because there are no other paths for the light to take through the cluster. “It’s going to be sad when it finally fades away.”