Astronomers Spot the Brightest Fast Radio Burst Ever Detected and Observe Stars Around Its Origin for the First Time

Using two telescopes, scientists were able to pinpoint the location of the fleeting phenomenon with surprising accuracy

Sara Hashemi | Daily Correspondent

August 26, 2025

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In March, astronomers detected a quick, powerful burst of radio energy that lit up in the sky for only a fraction of a second. Now, an international team of scientists has determined its origin with unprecedented speed and accuracy.

Fast radio bursts (FRBs) are massive flashes of radio waves that last just a few milliseconds. That makes them hard for scientists to study, since they disappear so quickly and are usually one-offs—very few of them repeat. But now, thanks to two powerful telescopes, scientists have been able to gain a little more insight into this mysterious phenomenon. Their findings were shared in two new papers published in the Astrophysical Journal Letters last week.

The March FRB was detected by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope in British Columbia, Canada. The burst was dubbed “RBFLOAT,” or the “Radio Brightest FLash Of All Time.”

Until recently, the array of radio receivers that make up CHIME was not able to identify the source of any given FRB. But thanks to the recent completion of a network of “Outrigger” telescopes in British Columbia, West Virginia and California, researchers were able to improve the array’s precision. They traced the origin of this burst to the edge of a star-forming region in a spiral galaxy called NGC 4141, located about 130 million light-years from Earth in the constellation Ursa Major. That makes it one of the closest FRBs ever detected.

Even though this burst was relatively nearby, pinning down its location was no easy feat. “Imagine we are in New York and there’s a firefly in Florida that is bright for a thousandth of a second, which is usually how quick FRBs are,” explains Shion Andrew, an astrophysicist at MIT and member of the research team, in a statement from the university. “Localizing an FRB to a specific part of its host galaxy is analogous to figuring out not just what tree the firefly came from, but which branch it’s sitting on.”

Put another way, spotting this fast radio burst was like seeing a quarter from a distance of more than 62 miles.

Because scientists traced the FRB so quickly, this work marked the first time researchers were able to follow up on the observation with the James Webb Space Telescope, writes Space.com’s Robert Lea. In the second study, scientists matched the burst with an infrared signal captured by the powerful telescope, located near the area from which the burst originated.

This infrared glow, astronomers suggest, comes from either a red giant star or a massive, middle-aged star—and it hints at what might have caused the FRB.

“The high resolution of JWST allows us to resolve individual stars around an FRB for the first time,” says Peter Blanchard, a researcher at the Center for Astrophysics, Harvard and Smithsonian, who led that work, in a statement. “This opens the door to identifying the kinds of stellar environments that could give rise to such powerful bursts, especially when rare FRBs are captured with this level of detail.”

Scientists still don’t know what causes FRBs. A leading theory is that they’re related to magnetars, or highly magnetic neutron stars left over from supernova explosions. While the newly detected red giant or massive star close to the radio burst’s origin might not have caused the FRB itself, it’s possible that an unseen companion to that star, like a neutron star pulling material away from its host, may have caused the FRB, according to a statement from the Center for Astrophysics.

Another possibility is that a massive star located in a cluster near the FRB had already collapsed into a magnetar, which might have caused the burst. “Whether or not the association with the star is real, we’ve learned a lot about the burst’s origin,” Blanchard says in the statement. “If a double star system isn’t the answer, our work hints that an isolated magnetar caused the FRB.”

While scientists still have a lot to uncover about FRBs, it’s clear that these powerful space telescopes can help them learn more in future work.

“For years, we’ve known FRBs occur all over the sky, but pinning them down has been painstakingly slow. Now, we can routinely tie them to specific galaxies, even down to neighborhoods within those galaxies,” says Yuxin Dong, an astronomer at Northwestern University and member of the research team, in another statement.

Sara Hashemi | Read More

Sara Hashemi is a science writer and fact-checker currently based in New York City. Her work has appeared in Sierra, The Body, Maisonneuve magazine and more.