GRB 250702B lasted for about a day\u2014an unusually long duration for a phenomenon like this. Astronomers believe that its source is a galaxy about a few billion light-years away, but that\u2019s just about all they know right now about a potential source.<\/p>\n
Too long to be true <\/p>\n
GRBs are short-lived because \u201cthe event that produces them is catastrophic,\u201d Martin-Carillo, an astronomer at University College Dublin in Ireland, said. It therefore doesn\u2019t make a lot of sense for the same (already \u201cdead\u201d) source to create repeated bursts.<\/p>\n
That\u2019s why GRB 250702B is so confusing. This odd burst, first captured by NASA\u2019s Fermi Gamma-ray Space Telescope<\/a>, arrived at Earth not once but three times over the course of several hours, which made its lifespan already record-breakingly long. Later, when researchers with Fermi compared notes with the Einstein Probe<\/a> team, the astronomers were shocked to learn that the same source had actually been active nearly a full day earlier.<\/p>\n If that wasn\u2019t surprising enough, the researchers now think the powerful radiation detected from GRB 250702B may actually be weaker than its true form. At first, they believed it came from within our own galaxy, but follow-up observations with the Hubble Space Telescope suggest it originated much farther out in the universe.<\/p>\n \u201cWhat we found was considerably more exciting: the fact that this object is extragalactic means that it is considerably more powerful,\u201d said Martin-Carrillo.<\/p>\n Stars only live once\u2026? <\/p>\n Cosmic entities are remarkably durable, but even stars aren\u2019t exempt from the rule that death only strikes once. So, if GRB 250702B originated from a massive star collapsing into itself, which is the going theory for GRBs in general, \u201cit is a collapse unlike anything we have ever witnessed before,\u201d said Andrew Levan, paper co-lead author and an astronomer at Radboud University in The Netherlands, in the same release.<\/p>\n Still, a star collapse as we know it should have created a GRB that lasted for only a few seconds. Theoretically, a star being ripped to shreds by a black hole could generate a day-long GRB. But for this hypothesis to hold, it would require an unusually strange black hole gobbling up an equally strange star\u2014a scenario that\u2019s theoretically possible, but one the researchers aren\u2019t yet able to confirm.<\/p>\n![\"Evolution](\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/09\/GRB-250702B-gamma-ray-burst-evolution-chart.jpg\")
This sequence of images shows the evolution over several days of the gamma-ray burst GRB 250702B. This GRB was first observed with high-energy telescopes on 2 July, which detected several flares of gamma rays over the course of a day. Credit: ESO\/A. Levan, A. Martin-Carrillo et al.\/NASA\/ESA <\/p>\n