In a study published in the The Astrophysical Journal, an international team of astronomers confirmed the most distant supernova ever confirmed by spectroscopic measurements. The Supernova was Located some 10.5 billion light-years from Earth, this massive star exploded when the universe was just a quarter of its current age of 13.8 billion years.
A supernova explosion occurs when a massive star runs out of fuel and collapses in on itself due to the pull of gravity. If the star is not massive enough to form a black hole (less than around 20 solar masses), then its collapsing core eventually rebounds off itself and bursts outward in what we see as a supernova.
The event is classified as a superluminous supernova (SLSN), the brightest and rarest of all known supernova types. It is at least 10 times brighter than the standard supernova and researchers believe it was caused by material falling onto a neutron star until it collapsed under its own weight.
“It’s thrilling to be part of the survey that has discovered the oldest known supernova. DES16C2nm is extremely distant, extremely bright, and extremely rare – not the sort of thing you stumble across every day as an astronomer,” lead author of the study Dr Mathew Smith, of the University of Southampton, said in a statement. “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.”
The researchers used the light from the explosion to understand what kind of elements were produced in these events and the temperatures at which they occurred. They hope to better characterize this type of supernova, which has only been known about for the last 15 years.
DES16C2nm was detected by the Dark Energy Survey, an international collaboration that’s mapping the position of several hundred million galaxies in three-dimensional space to learn about the properties of dark energy. Dark energy is believed to be responsible for the accelerated expansion of the universe.
“Such supernovae were not thought of when we started DES over a decade ago. Such discoveries show the importance of empirical science; sometimes you just have to go out and look up to find something amazing,” co-author Professor Bob Nichol, from the University of Portsmouth, added.
The survey covers an area of the sky measuring 5,000 square degrees, an area equivalent to 25,000 times the full Moon in the sky. The team is now going to look for more of these events in the survey.