Light from the supernova seen behind the galaxy cluster Abell 370. | SkyNews
Light from the supernova seen behind the galaxy cluster Abell 370 (Wenlei Chen, NASA)

Red supergiant supernova found behind galaxy cluster Abell 370

The cluster’s gravity created a lensing effect that warped and bent the light.

Astronomers discovered a supernova from a star that exploded 11.5 billion years ago.

The international research team, led by the University of Minnesota in the United States, said it is the furthest supernova yet to be observed. The data could help astronomers learn more about the stars and galaxies in the early universe.

“The images we captured show the supernova as it was at different ages separated by several days,” said Patrick Kelly, lead author of a paper in the journal Nature describing the discovery, in a statement. 

The light of the explosion was warped thanks to a phenomenon called gravitational lensing. Hubble detected different months of the explosion simultaneously. The images also show the cooling remains of the red supergiant, which swelled to 500 times larger than our Sun when it exploded.

“We see the supernova rapidly cooling, which allows us to basically reconstruct what happened and study how the supernova cooled in its first few days with just one set of images,” said Kelly. “It enables us to see a rerun of a supernova.”

The Hubble Space Telescope and Large Binocular Telescope collected data on a galaxy cluster called Abell 370 that was being studied by the team. They found that the cluster was in front of the supernova. The cluster’s gravity created a lensing effect that warped and bent the light, allowing separate stages of the explosion to be seen at once.

“We can learn in detail about an individual star when the universe was less than a fifth of its current age, and begin to understand if the stars that existed many billions of years ago are different from the ones nearby,” said Kelly.

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