On August 26, 2020, NASA’s Fermi Gamma-ray Space Telescope detected a pulse of high-energy radiation that had been racing toward Earth for nearly half the present age of the universe. Lasting only about a second, it turned out to be one for the record books – the shortest gamma-ray burst (GRB) caused by the death of a massive star ever seen.

GRBs are the most powerful events in the universe, detectable across billions of light-years. Astronomers classify them as long or short based on whether the event lasts for more or less than two seconds. They observe long bursts in association with the demise of massive stars, while short bursts have been linked to a different scenario.

Astronomers combined data from NASA’s Fermi Gamma-ray Space Telescope, other space missions, and ground-based observatories to reveal the origin of GRB 200826A, a brief but powerful burst of radiation. It’s the shortest burst known to be powered by a collapsing star – and almost didn’t happen at all. Credit: NASA’s Goddard Space Flight Center.