The newly-discovered core-collapse supernova, or Type II supernova, seen at a lookback time of approximately 11.5 billion years, is strongly lensed by a member galaxy in the massive galaxy cluster Abell 370. The radius of the exploded star is estimated to be 533 times the radius of the Sun, consistent with a red supergiant.
A multiply imaged supernova in the archival Hubble imaging of the Abell 370 galaxy-cluster field. Image credit: Chen et al., doi: 10.1038/s41586-022-05252-5.
“This is the first detailed look at a supernova at a much earlier epoch of the Universe’s evolution,” said Dr. Patrick Kelly, an astronomer with the University of Minnesota.
“It’s very exciting because 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.”
Using data from the NASA/ESA Hubble Space Telescope and the Large Binocular Telescope, Dr. Kelly and his colleagues were able to identify three separate gravitationally lensed images of the exploded star.
“The gravitational lens acts as a natural magnifying glass and multiplies Hubble’s power by a factor of eight,” Dr. Kelly explained.
“Here, we see three images. Even though they can be seen at the same time, they show the supernova as it was at different ages separated by several days.”
The exploded star is a red supergiant about 533 times larger than the Sun, and is located at redshift of 3, which is about 60 times farther away than any other supernova observed in this detail.
“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. It enables us to see a rerun of a supernova,” Dr. Kelly.
Dr. Kelly and co-authors combined their new discovery with another one from 2014 to estimate how many stars were exploding when the Universe was a small fraction of its current age.
They found that there were likely many more supernovae than previously thought.
“Core-collapse supernovae are catastrophic explosions of massive, short-lived stars,” said Dr. Wenlei Chen, a postdoctoral researcher at the University of Minnesota.
“The number of core-collapse supernovae we detect can be used to understand how many massive stars were formed in galaxies when the Universe was much younger.”
The results appear today in the journal Nature.
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W. Chen et al. 2022. Shock cooling of a red-supergiant supernova at redshift 3 in lensed images. Nature 611, 256-259; doi: 10.1038/s41586-022-05252-5
