Astronomers have discovered a supernova that occurred 10.5 billion years ago, when the Universe was less than a quarter of its present age.
DES16C2nm. Image credit: M. Smith / DES Collaboration.
The record-breaking supernova was detected in 2016 by the Dark Energy Survey (DES), an international collaboration to map several hundred million galaxies in order to find out more about dark energy.
Named DES16C2nm, it belongs to a special class called hydrogen-free superluminous supernova (SLSN-I).
“Such supernovae were not thought of when we started DES over a decade ago,” said co-author Professor Bob Nichol, from the University of Portsmouth.
“Such discoveries show the importance of empirical science; sometimes you just have to go out and look up to find something amazing.”
“It’s thrilling to be part of the survey that has discovered the oldest known supernova,” added lead author Dr. Mathew Smith, from the University of Southampton.
“DES16C2nm is extremely distant, extremely bright, and extremely rare — not the sort of thing you stumble across every day as an astronomer.”
“As well as being a very exciting discovery in its own right, the extreme distance of DES16C2nm gives us a unique insight into the nature of SLSN,” Dr. Smith said.
“The ultraviolet light from SLSN informs us of the amount of metal produced in the explosion and the temperature of the explosion itself, both of which are key to understanding what causes and drives these cosmic explosions.”
Finding more distant events, to determine the variety and sheer number of these events, is the next step.
“Now we know how to find these objects at even greater distances, we are actively looking for more of them as part of DES,” said co-author Professor Mark Sullivan, also from the University of Southampton.
The findinds are published in the Astrophysical Journal.
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M. Smith et al. 2018. Studying the Ultraviolet Spectrum of the First Spectroscopically Confirmed Supernova at Redshift Two. ApJ 854, 37; doi: 10.3847/1538-4357/aaa126
