James Webb Space Telescope confirms earliest supernova to date
Thanks to sufficient advance warning, the James Webb Space Telescope was able to study the earliest supernova by far. A gamma-ray burst had announced it.
Artistic representation of the developing gamma-ray burst and the supernova itself
(Image: NASA, ESA, CSA, STScI, L. Hustak (STScI))
The James Webb Space Telescope has significantly surpassed the record for the most distant supernova, observing a stellar explosion that occurred 730 million years after the Big Bang. This was possible because a gamma-ray burst was detected first, giving the instrument enough time to target the event and search for optical signals. Three and a half months after the gamma-ray burst, the space telescope was therefore able to observe the supernova at its brightest point, officials now explain. The researchers were reportedly surprised by how much the explosion resembled those we know from the present-day universe.
(Image:Â NASA, ESA, CSA, STScI, A. Levan (IMAPP), Image Processing: A. Pagan (STScI))
Sufficient preparation time thanks to immense distance
According to officials for the space telescope, the initial gamma-ray burst was detected on March 14, 2025, and follow-up observations were immediately initiated. Just four hours later, the distance to the event was reportedly determined using the European Southern Observatory's Very Large Telescope. Since only a few gamma-ray bursts from the time when the universe was less than a billion years old have been discovered so far, this was already very exciting. While the gamma-ray bursts of a supernova only last seconds or minutes, the light afterward can usually be observed for weeks. However, because it had traveled for so long in this case and was stretched, there was enough time to later orient the James Webb Space Telescope towards it.
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The subsequent analyses suggest that the galaxy in which the explosion occurred resembles others from that era. The fact that the supernova is so similar to more modern ones was surprising, as stars were built noticeably differently back then. The research team is now hoping for further data to find differences after all. However, they already suspect that it was the explosive end of a massive star. Two scientific articles on the discovery have now been published in the scientific journal Astronomy & Astrophysics. The research group also points out that the oldest supernova to date occurred 1.8 billion years after the Big Bang.
(mho)
