An international team of astronomers has reached a historic milestone in the study of the early universe.

Using the James Webb Space Telescope (JWST), they have detected the most distant supernova ever discovered. A supernova is the explosive death of a giant star.

The explosion occurred when the universe was only about 730 million years old. This period is called the ‘reionization period’, when the earliest galaxies were just beginning to form.

The event was first detected on March 14, 2025, but not by directly observing the explosion, but by a powerful burst of extremely powerful radiation, called a gamma-ray burst (GRB). The signal was recorded by the space-based SVOM monitor.

About 110 days later, scientists turned to the James Webb Space Telescope at the same location. They successfully separated the light from the explosion from its very faint host galaxy, confirming that a supernova had indeed occurred.

Co-author Dr Antonio Martin Carrillo of the study called the discovery “decisive evidence” that directly links the deaths of giant stars to gamma-ray bursts.

He said that the supernovae we have studied so far have almost all been relatively close to us. When we confirmed the age of this supernova, we had a rare opportunity to learn what kind of stars existed at that time and how they died.

The most surprising thing was that this explosion, which occurred so anciently, has almost the same characteristics as supernovae seen in the modern universe today.