Gamma-ray bursts (GRBs) are powerful bursts of high-energy radiation that come from space. They were first discovered in the 1960s by U.S. military satellites designed to spot nuclear explosions. Instead, they found bright flashes of gamma rays in the sky. At first, no one knew what these mysterious signals were, but eventually, astronomers started to piece together their origins.
In 2025, a remarkable burst, named GRB 250702B, was detected. It lasted for an incredible seven hours, making it unique among GRBs. To learn more, we spoke with Eliza Neights, a researcher at NASA Goddard Space Flight Center, who studies these cosmic phenomena.
“We detect GRBs primarily using telescopes that monitor large areas of the sky,” Eliza explains. These instruments can pick up sudden bright flashes, which prompts researchers to analyze the events.
When GRB 250702B was detected, it was unusual. Eliza was on duty and noted it had three separate bursts from the same location in the sky. “This GRB lasted about 25,000 seconds—much longer than the average GRB, which typically lasts just a few minutes,” she says. The previous record holder lasted around 15,000 seconds, so this new finding poses interesting questions. What could explain such a long duration?
Most GRBs we know about arise from the collapse of massive, rapidly spinning stars, leading to the formation of black holes that shoot out jets. The other common source is the merger of two neutron stars, which also creates jets detectable as GRBs.
For the long-lasting GRB 250702B, researchers think it might be caused by a “helium merger.” This happens when a black hole orbits a helium-rich star, consuming its outer layers, which releases a burst of energy that lasts much longer than usual. “It’s like a cosmic feeding frenzy,” Eliza suggests.
Such long bursts may not be very common, and they can be hard to detect because they tend to be dimmer and quantum telescopes often focus on bright, quick signals.
Looking ahead, Eliza is excited about her work with the upcoming Compton Spectrometer and Imager (COSI) telescope, set to launch in 2027. This new telescope will help researchers study GRBs in more detail and maybe catch more of these long bursts in the future.
Gamma-ray bursts continue to be a hot topic among scientists. As they unravel their mysteries, we gain a deeper understanding of the universe and its most extreme events. Recent studies, like those published in Science Magazine, indicate that continued exploration may reveal more about what fuels these dramatic cosmic explosions.
