NASA’s Fermi telescope has detected what may be the first confirmed gamma-ray signal from a superluminous supernova — one of the most extreme explosions in the universe. Scientists believe the blast was powered by a rapidly spinning magnetar, an exotic neutron star with unbelievably strong magnetic fields. The event, called SN 2017egm, erupted 440 million light-years away and may help explain why some supernovae become extraordinarily bright.

NASA’s Fermi Gamma-ray Space Telescope may have finally uncovered what powers some of the brightest stellar explosions ever observed. After studying years of data, an international research team found strong evidence that a rare superluminous supernova was energized by an extremely magnetic neutron star formed during the star’s collapse.

The Fermi mission is part of NASA’s network of observatories designed to track changing events across the universe and help scientists better understand how cosmic phenomena work.