‘Root beer FLOAT’ star burst’s is located with extraordinary precision\” />
An international team of scientists, including Northwestern University astrophysicists, has spotted one of the brightest fast radio bursts (FRBs) ever recorded — and pinpointed its location with unprecedented precision,
A newly detected FRB is one of the brightest ever observed. To discover this, astronomers used the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope array to triangulate the burst’s location.
CHIME is a novel radio telescope that has no moving parts. Originally conceived to map the most abundant element in the universe – hydrogen – over a good fraction of the observable universe, this unusual telescope is optimised to have a high “mapping speed”, which requires a large instantaneous field of view.
The millisecond-long blast — nicknamed by the researchers as ‘RBFLOAT’ (short for “radio-brightest flash of all time” and, yes, a nod to “root beer float”) — was discovered by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) and its newly completed “Outrigger” array. By combining observations from sites in British Columbia, West Virginia and California, scientists traced the burst to a single spiral arm of a galaxy 130 million light-years away — accurate within just 42 light-years.
Since they occur so far away and vanish within the blink of an eye, FRBs are notoriously difficult to study. If scientists can pinpoint an FRB’s exact location, however, they can explore its environment, including characteristics of its home galaxy, distance from Earth and potentially even its cause. Eventually, this information could help shed light on the nature and origins of these mysterious, fleeting bursts.
“It is remarkable that only a couple of months after the full Outrigger array went online, we discovered an extremely bright FRB in a galaxy in our own cosmic neighborhood,” said Northwestern’s Wen-fai Fong, a senior author on the study in a research note.
Flaring up and disappearing within milliseconds, FRBs are brief, powerful radio blasts that generate more energy in one quick burst than our sun emits in an entire year. While most pass unnoticed, every once in a while, an FRB is bright enough to detect. FRB20250316A, or RBFLOAT, was one of these rare events. Detected in March 2025, RBFLOAT released as much energy in a few milliseconds as the sun produces in four days.
“This bodes very well for the future. An increase in event rates always provides the opportunity for discovering more rare events. The CHIME/FRB collaboration worked for many years toward this technical achievement, and the universe rewarded us with an absolute gift.”
“This result marks a turning point,” said corresponding author Amanda Cook, a postdoctoral researcher at McGill University. “Instead of just detecting these mysterious flashes, we can now see exactly where they are coming from. It opens the door for discovering whether they are caused by dying stars, exotic magnetic objects or something we haven’t even thought of yet.”
To investigate RBFLOAT’s origin, the scientists relied on CHIME, a large radio telescope in British Columbia and the world’s most prolific FRB hunter. Smaller versions of CHIME, the Outriggers enable astronomers to triangulate signals to precisely confine the specific locations of FRBs on the sky.
With this array of vantage points, the team traced the burst to the Big Dipper constellation in the outskirts of a galaxy about 130 million light-years away from Earth. The team precisely pinpointed it to a region just 45 light-years across, which is smaller than an average star cluster.
Follow-up observations from the 6.5-meter MMT telescope in Arizona and the Keck Cosmic Web Imager on the 10-meter Keck II Telescope in Hawai‘i provided the most detailed view yet of a non-repeating FRB’s surroundings.
The investigations revealed the burst occurred along a spiral arm of the galaxy, which is dotted with many star-forming regions. The RBFLOAT occurred near, but not inside, one of these star-forming regions. Although astrophysicists still don’t know exactly what causes FRBs, this evidence bolsters one leading hypothesis. At least some appear to come from magnetars, ultra-magnetized neutron stars born from the deaths of massive stars. Star-forming regions often host young magnetars, which are energetic enough to produce quick, powerful bursts.
The research is set to be published in the journal The Astrophysical Journal Letters.
