Key Highlights
- NASA satellites and other facilities discovered an unprecedented cosmic outburst lasting days.
- The event, named GRB 250702B, is the longest gamma-ray burst ever observed by scientists.
- Researchers propose that a black hole consumed a star in one of two scenarios: a massive tidal disruption or a merger with its companion.
- NASA’s James Webb Space Telescope provided unprecedented details about the galaxy hosting the explosion, located 8 billion light-years away.
Unprecedented Cosmic Outburst: The Longest Gamma-Ray Burst Ever Observed
NASA’s latest discovery in cosmic exploration has sent ripples through the scientific community. On July 2, 2025, a record-setting gamma-ray burst (GRB) was detected by multiple NASA missions and other observatories, marking what may be one of the longest and most powerful explosions ever recorded.
This extraordinary event, named GRB 250702B, has captivated astronomers due to its unprecedented duration. While typical gamma-ray bursts last only a few minutes, this burst continued for over seven hours—nearly twice as long as the previous record holder. This extended duration poses significant challenges and opens up new questions about the nature of these cosmic phenomena.
Understanding the Phenomenon
Eliza Neights from George Washington University and NASA’s Goddard Space Flight Center, along with her team, shared their findings at a recent meeting of the American Astronomical Society’s High Energy Astrophysics Division in St. Louis, Missouri. Their research suggests that this extraordinary burst could be an indicator of new types of stellar explosions or cosmic events.
The initial gamma-ray signal lasted for at least seven hours, triggering multiple instruments on various NASA satellites and observatories. These included the Fermi Gamma-ray Space Telescope’s Gamma-ray Burst Monitor (GBM), the Swift Observatory’s Burst Alert Telescope, and the International Space Station’s Monitor of All-sky X-ray Image instrument.
Decoding the Source
The extended duration of GRB 250702B posed a unique challenge for scientists, as no single satellite was equipped to observe it in its entirety. Instead, the combined data from multiple spacecraft provided a comprehensive view of this cosmic event.
The Wide-field X-ray Telescope on China’s Einstein Probe detected an earlier signal, suggesting that the burst had been present even before it was officially observed. This information, coupled with data from ground-based observatories like those at the Keck and Gemini telescopes in Hawaii and the European Southern Observatory’s Very Large Telescope (VLT) in Chile, led scientists to identify a galaxy as the host of this extraordinary event.
NASA’s Hubble Space Telescope played a crucial role in confirming that the burst originated from a distant galaxy.
Andrew Levan, an astrophysics professor at Radboud University in the Netherlands, and his team used Hubble data to determine that this was indeed a distant and powerful explosion, yet one with peculiar characteristics.
More detailed observations from NASA’s James Webb Space Telescope revealed unprecedented clarity about the host galaxy. Huei Sears, a postdoctoral researcher at Rutgers University, led these observations, which showed the burst shining through a dust lane in the galaxy. This provided valuable insights into the nature of this extraordinary explosion and its host environment.
Exploring Possible Scenarios
The data collected from various NASA missions suggest two possible scenarios for what caused GRB 250702B. One theory involves a black hole consuming a star through tidal disruption, while another proposes the merging of a smaller black hole with its stellar companion.
According to Benjamin Gompertz, who led a team using Webb’s NIRSpec instrument and the VLT, the host galaxy is surprisingly large, which challenges conventional models. This finding implies that GRB 250702B may be associated with a rarely observed “middleweight” black hole—much larger than those formed from stellar collapse but smaller than supermassive black holes found at the centers of galaxies.
While smoking-gun evidence remains to be confirmed, this event has already provided significant new insights into the nature and mechanisms behind long-duration gamma-ray bursts.
The continuous monitoring by NASA’s fleet of observatories continues to uncover new mysteries in our quest to understand the cosmos better.
The research on GRB 250702B is being published across several papers, including studies from the Neights-led gamma-ray team, Gompertz’s NIRSpec paper, Carney’s supernova investigation, and O’Connor’s X-ray analysis. These findings contribute to our understanding of black hole behavior and the complex processes that govern stellar explosions in distant galaxies.
With ongoing research and continued monitoring by NASA and other space agencies, future discoveries are likely to shed more light on these fascinating cosmic phenomena. The study of GRB 250702B not only challenges our current understanding but also paves the way for new discoveries in the field of astrophysics.
