Imagine witnessing a cosmic event that lasts nearly seven hours—something astronomers had never seen before! This incredible phenomenon, dubbed GRB 250702B, is not just another gamma-ray burst; it shattered previous records and has left scientists reevaluating everything they thought they knew about our universe.

Gamma-ray bursts (GRBs) are the universe’s most explosive events, typically flickering out in mere minutes or seconds. But GRB 250702B, which lit up the cosmic stage on July 2, 2025, continued to blaze for an astonishing 25,000 seconds, outlasting the previous record-holder, GRB 111209A, by almost three hours. This makes GRB 250702B the longest-lasting GRB ever recorded, prompting researchers to rethink the very nature of these celestial fireworks.

When the NASA Fermi Gamma-ray Burst Monitor first detected an unusual signal, astronomers quickly recognized it was something extraordinary. As more data poured in from observatories like Japan’s Einstein Probe and the Konus-Wind detector, it confirmed that this extended event was unlike anything previously recorded. It was a cosmic explosion that repeated several times throughout the day, captured in stunning detail by the Very Large Telescope (VLT).

Researchers, a collective of over 50 astrophysicists from around the globe, embarked on an extensive investigation to understand the source of this unprecedented gamma-ray eruption. They ruled out various theories, including magnetar flares and neutron-star mergers, which ultimately led them to a compelling conclusion: a helium-merger event.

This model suggests that two massive stars spiraled around each other until one collapsed into a black hole. As the black hole sank into the expanding stellar atmosphere of its companion, it created an accretion disk, thrusting material inward and launching twin jets at nearly the speed of light. This sequence lasted for tens of thousands of seconds, producing the gamma rays observed from Earth.

Interestingly, astronomers expected to find a supernova explosion at the site weeks later, but to their astonishment, there was nothing—no glowing remnants, nothing at all. This absence of evidence further supported the helium-merger model, which posits that the conditions for producing the bright isotopes typically seen in supernovae were simply not met.

The success of this groundbreaking discovery was a testament to international collaboration, featuring specialists like Eliza Neights and Eric Burns, who worked tirelessly to analyze the event. The findings were made possible with support from various institutions, including NASA and the United States–Israel Binational Science Foundation.

With GRB 250702B now shining a light on new high-energy astronomy dimensions, scientists are not just recording cosmic explosions—they're rewriting the fundamental rules of stellar evolution and black hole formation. This revelation may link gamma-ray bursts and the gravitational waves detected by observatories like LIGO, opening pathways to comprehend how elements and life itself are distributed across the universe.

As we await future missions, such as the Vera Rubin Observatory, experts predict they will unveil even more extraordinary gamma-ray bursts, providing richer insights into the life cycles of the stars that give rise to these magnificent displays.

Such breakthroughs not only redefine our cosmic understanding but could also refine models of supernovae and enhance predictions about gravitational waves. In essence, they help us piece together the sprawling puzzle of the universe.