Astronomers Investigate Unprecedented Seven-Hour Gamma-Ray Burst
Scientists are analyzing GRB 250702B, a gamma-ray burst lasting over seven hours, to understand its unique characteristics and origin.
On July 2, 2025, astronomers detected an extraordinary gamma-ray burst (GRB) named GRB 250702B, which lasted approximately seven hours—significantly longer than typical GRBs that usually last from milliseconds to minutes.
The event was first identified by NASA's Fermi Gamma-ray Space Telescope, which recorded multiple bursts from the same source over several hours. Subsequent observations by China's Einstein Probe revealed that the activity had commenced nearly a day earlier.
To determine the burst's origin, scientists utilized the European Southern Observatory's Very Large Telescope (VLT) and NASA's Hubble Space Telescope. These observations confirmed that GRB 250702B occurred in a galaxy beyond the Milky Way, potentially several billion light-years away.
The prolonged duration and repeating nature of GRB 250702B challenge existing models of gamma-ray bursts. Antonio Martin-Carrillo, an astronomer at University College Dublin, noted that this event is "unlike any other seen in 50 years of gamma-ray burst observations."
Researchers are considering various explanations, including the possibility of a massive star collapsing in an unprecedented manner or a white dwarf being torn apart by an intermediate-mass black hole. However, none of these scenarios fully account for the observed characteristics.
Ongoing studies aim to unravel the mechanisms behind this unique cosmic event, with hopes that further observations will provide clarity on its origin and implications for our understanding of gamma-ray bursts.