Astronomers have detected an explosion of gamma rays that repeated several times over the course of a day, an event unlike anything ever witnessed before. The source of the powerful radiation was discovered to be outside our galaxy, its location pinpointed by the European Southern Observatory’s Very Large Telescope (VLT). Gamma-ray bursts (GRBs) are the most powerful explosions in the Universe, normally caused by the catastrophic destruction of stars. But no known scenario can completely explain this new GRB, whose true nature remains a mystery – Read the full story on:
The orange dot at the centre of this image is a powerful explosion that repeated several times over the course of a day, an event unlike anything ever witnessed before. The image, taken with ESO’s Very Large Telescope (VLT), allowed astronomers to determine that the explosion didn’t take place in the Milky Way but in another galaxy. This gamma-ray burst, named GRB 250702B, was first spotted by high-energy telescopes on 2 July, but its location was uncertain. The image shown here was taken on 3 July with the VLT’s HAWK-I infrared camera, which accurately pinpointed the location of the source. The explosion appeared to be nested within another galaxy, later confirmed by the NASA/ESA Hubble Space Telescope. Different scenarios have been proposed to explain this event, such as the collapse of a massive star, or a star ripped apart by a black hole. But none of them can fully account for all the observed properties of the explosion unless the involved objects are rather unusual – Credit: ESO/A. Levan, A. Martin-Carrillo et al.
