The James Webb Space Telescope and other international observatories have spotted a 13-billion-year-old supernova. On Tuesday, the European Space Agency (ESA) announced the sighting of a gamma-ray burst from a star that exploded when the Universe was only 730 million years old. The Webb telescope even detected the supernova’s host galaxy.
Before this observation, the oldest recorded supernova was from when the Universe was 1.8 billion years old. That’s a difference of more than a billion years.
You can see the gamma-ray burst in the image below. It’s the tiny red smudge at the center of the zoomed-in box on the right.
The tiny red splotch in the center of the crop box is the oldest thing you’ve seen. (NASA, ESA, CSA, STScI, A. Levan (IMAPP))
“This observation also demonstrates that we can use Webb to find individual stars when the Universe was only 5 percent of its current age,” co-author Andrew Levan wrote in the ESA’s press release. “There are only a handful of gamma-ray bursts in the last 50 years that have been detected in the first billion years of the Universe. This particular event is very rare and very exciting.”
Researchers learned that the 13-billion-year-old explosion shared many traits with modern, nearby supernovae. While that may not sound shocking, scientists expected a more profound difference. That’s because early stars likely had fewer heavy elements, were more massive and didn’t live as long. “We went in with open minds,” co-author Nial Tanvir said. “And lo and behold, Webb showed that this supernova looks exactly like modern supernovae.”
Detection was an international relay race. First, NASA’s Neil Gehrels Swift Observatory noted the X-ray source’s location. (That helped Webb to make subsequent observations that determined its distance). Then, the Nordic Optical Telescope on the Canary Islands in Spain made observations indicating that the gamma ray might be very distant. Hours later, the European Southern Observatory’s Very Large Telescope in Chile estimated its age: 730 million years after the Big Bang. All of this happened in under 17 hours, according to the ESA.
The team behind the observation has been approved to spend more time with Webb studying gamma-ray bursts from the early Universe — and the galaxies behind them. “That glow will help Webb see more and give us a ‘fingerprint’ of the galaxy,” Levan predicted.