The James Webb Space Telescope has captured the light from the oldest supernova ever observed, a stunning event that took place 13 billion years ago, just 730 million years after the Big Bang. This supernova was linked to a powerful gamma-ray burst (GRB), which marks the violent end of a massive star and hints at the formation of a stellar-mass black hole.
Andrew Levan, a researcher at Radboud University in the Netherlands and the University of Warwick in the U.K., stated, “In the last 50 years, only a few GRBs from the universe’s first billion years have been detected. This event is rare and incredibly exciting.” These bursts provide insights into the early universe’s chaotic landscape.
The story begins on March 14. The French-Chinese SVOM satellite detected a gamma-ray flare from deep space. Shortly after, NASA’s Neil Gehrels Swift Observatory picked up the same burst in X-rays, allowing astronomers to locate the event, designated GRB 250314A. Eleven hours later, the Nordic Optical Telescope in the Canary Islands spotted the fading light of the GRB’s afterglow. Finally, the Very Large Telescope in Chile confirmed that this light was from a supernova, revealing it had a redshift of 7.3. This redshift indicates we are seeing an event that happened 13 billion years ago.
Interestingly, due to the expanding universe, the light from this explosion takes longer to reach its peak brightness from our perspective. It wouldn’t appear fully bright for about three and a half months. This helps us understand how far away these events are in time and space.
Levan led a team to use the James Webb Space Telescope for a closer look. By July 1, they successfully detected the light from the supernova, affirming it was indeed from a collapsing star. “Only Webb could capture this,” Levan remarked, highlighting its ability to explore the universe’s earliest moments — just 5% of its current age. The JWST also identified the supernova’s host galaxy, giving researchers clues about the environment in which this cosmic event occurred.
Emeric Le Floc’h from CEA Paris-Saclay noted that the distant galaxy appears quite similar to other galaxies from that period. Further analysis suggests that the supernova’s explosion is comparable to modern-day supernovas, although it took place in a time when heavy elements were much scarcer. More studies will help clarify these potential differences.
This supernova sets a new record for distance, surpassing a previously observed supernova that erupted 1.8 billion years after the Big Bang. It’s one of only a few GRBs detected from the first billion years of the universe. These findings were recently published in the journal Astronomy & Astrophysics.
As we continue to explore the universe, these discoveries remind us of how little we still know. The reactions from the scientific community highlight the excitement of witnessing the birth and death of stars, shedding light on our cosmic history.
