Astronomers using the James Webb Space Telescope have discovered AT 2026abck, which may be one of the most distant supernovas, or exploding stars, ever observed. The explosion happened about 1.15 billion years after the Big Bang, when the universe was less than a tenth of its present age.
The researchers estimate that they saw the explosion as it looked just four to ten days after it began. At its brightest, it was about eight billion times as bright as the sun, almost matching the whole Milky Way galaxy. Finding such a distant explosion at this early stage required repeated observations of the same small area of sky and lucky timing.
Because the universe has expanded since the light began its journey, the event appears to unfold about six times more slowly. A week of changes at the explosion takes about six weeks for us to see. The team thinks this could be an unusually powerful type of supernova, but its explanation remains uncertain. Further observations could help identify the type of explosion and explain what caused it.
