Alison M. Laird

For seven hours straight, a space gamma-ray telescope registered flares that refused to end. That is how the story of GRB 250702B began: the longest gamma-ray burst ever observed. Typical bursts last seconds, rarely minutes. This one stretched to 25,000 seconds, beating the previous record by a factor of two.

Aluminum-26 is an isotope that doesn't live long by cosmic standards: only about a million years. When a massive star explodes as a supernova, it flings this aluminum into space. Later, it decays, emitting gamma rays that telescopes can catch. The authors recalculated how much aluminum-26 a star with 20 solar masses should eject.