Science News from research organizations Astronomers just found the source of the brightest fast radio burst ever Date: March 15, 2026 Source: University of Toronto Summary: Astronomers have discovered the brightest fast radio burst ever detected and traced it to a nearby galaxy using a new network of CHIME Outrigger telescopes. The flash, nicknamed RBFLOAT, lasted only a fraction of a second but briefly outshone every other radio source in its galaxy. Follow-up observations with the James Webb Space Telescope spotted a faint infrared signal at the same location. The burst’s unusual behavior—showing no signs of repeating—may challenge current ideas about what causes these mysterious cosmic flashes. Share: Facebook Twitter Pinterest LinkedIN Email FULL STORY Artist’s rendition of CHIME/FRB and its Outriggers localizing FRB 20250316A/ RBFLOAT. Inset: The host galaxy (NGC 4141) as imaged by MMT Observatory (PI: Yuxin (Vic) Dong), illustrating the location of the FRB within a spiral arm of NGC 4141. Credit: Danielle Futselaar An international team of astronomers, including researchers from the University of Toronto, has identified the brightest Fast Radio Burst (FRB) ever observed and traced its origin to a nearby galaxy using a coordinated network of radio telescopes. FRBs are among the most puzzling phenomena in astronomy, but locating where they come from with precision could mark the start of a new phase in research, allowing scientists to better understand their cosmic origins. Fast radio bursts are incredibly powerful flashes of radio energy that travel across vast distances in the universe. Scientists believe they are produced by extreme astrophysical events, though the exact cause remains uncertain. Since 2018, the Canadian Hydrogen-Intensity Mapping Experiment, or CHIME, has detected thousands of these bursts. However, determining their exact positions in the sky has remained a major challenge. CHIME Outrigger Array Pinpoints the Burst The newly detected signal, named FRB 20250316A and nicknamed RBFLOAT ("Radio Brightest Flash Of All Time"), was localized with remarkable precision using the CHIME/FRB Outrigger array. These smaller versions of the CHIME instrument are installed in British Columbia, Northern California and West Virginia. Working together, they allow astronomers to use Very Long Baseline Interferometry (VLBI), a technique that combines signals from widely separated telescopes to determine an object's position in the sky with exceptional accuracy. "We were ultimately extremely lucky that we were able to pinpoint the precise sky position of this rare event," said Mattias Lazda, doctoral student at the University of Toronto, and an author on both papers. "A few hours after we detected it, we experienced a power outage at one of our telescope sites that played a critical role in telling us where the burst came from. Had the event happened any later that day, we would've completely missed our chance." A Powerful Burst From a Nearby Galaxy Although fast radio bursts rank among the most intense radio sources known, they appear only briefly. Each burst typically lasts from a few milliseconds to a few seconds, temporarily shining brighter than every other radio signal in its host galaxy. RBFLOAT, detected on March 16, 2025, lasted about one fifth of a second. "Cosmically speaking, this fast radio burst is just in our neighborhood," says Kiyoshi Masui, associate professor of physics and affiliate of MIT's Kavli Institute for Astrophysics and Space Research, and a U of T alum. "This means we get this chance to study a pretty normal FRB in exquisite detail." The burst appeared exceptionally bright partly because its source lies relatively close to Earth. It originated near the outer region of the galaxy NGC 4141, located about 130 million light-years away in the constellation Ursa Major. Researchers were able to narrow the signal's origin to a region only 45 light-years across, which is smaller than the typical size of a star cluster. Achieving this level of precision is comparable to spotting a guitar pick from 1000 kilometers away. "The discovery was very exciting, because we had our brightest ever event right after all three outriggers were online," said Amanda Cook, Banting Postdoctoral Researcher at McGill University and a U of T alum who led the paper describing RBFLOAT. "Immediately, even though it was a Sunday afternoon, a bunch of us piled into a zoom room and started hacking away at the research, hoping to get follow-up observations on source as quickly as possible." JWST Observations Reveal a Faint Infrared Signal The precise location provided by the CHIME/FRB Outrigger array allowed the team to conduct follow-up observations with the James Webb Space Telescope (JWST). During those observations, scientists detected a faint infrared signal at the same location where RBFLOAT originated. The finding was unexpected, and rese