An international team of astronomers, including Franz Kirsten from Chalmers, have pinpointed the source of a record-bright burst of radio waves from another galaxy. Combining data from many telescopes, the scientists have made new progress in solving one of the biggest mysteries in astrophysics.
Fast radio bursts are intense flashes of radio waves from space that last only thousandths of a second. Since their discovery in 2007, scientists have detected hundreds, but what causes them remains unknown.
In March 2025, an exceptionally bright burst, labelled FRB 20250316A, was detected in the constellation Ursa Major with the Chime/FRB radio telescope in Canada. In just a few milliseconds, the burst released as much energy as the sun produces in four days, the scientists estimate.
The researchers were able to pinpoint the signal’s location on the sky with extreme precision, using the Chime’s newly operational network of outrigger telescopes, located across Canada and the United States.
Amanda Cook, astronomer at McGill University, Canada, led the study that announced the discovery.
“This result marks a turning point: instead of just detecting these mysterious flashes, we can now see exactly where they’re coming from. It opens the door to discovering whether they’re caused by dying stars, exotic magnetic objects, or something we haven’t thought of yet,” she says.
The burst came from the outskirts of galaxy NGC 4141. At 130 million light-years from Earth, it is the nearest non-repeating fast radio burst that has been precisely localised .
To investigate further, an international collaboration quickly mobilized a wide network of observatories. Radio telescopes across the globe – among them the 25-metre radio telescope in Onsala, Sweden - monitored the source for repeat bursts. The NASA/ESA/CSA James Webb Space Telescope provided the sharpest view, revealing a faint source of infrared light at the burst’s location.
The faint source identified by James Webb appears to be a star nearing the end of its life, a red giant or red supergiant. Although these stars are unlikely to directly produce FRBs, the scientists say, they may have an unseen companion, such as a neutron star.
“Compared to other potential sources we’ve found so far, here we’re looking a very different sort of star system. If fast radio bursts can happen in many different environments, then the underlying physics could be much simpler than we’ve thought,” says Franz Kirsten.
Previously discovered fast radio bursts have been attributed to neutron stars with strong magnetic fields, known as magnetars.
“This discovery shows how quickly and reliably radio telescopes like Chime can pin down fast radio bursts to their host galaxies, and with amazingly high precision. That’s what makes it possible to join forces with telescopes sensitive to other wavebands. Now we can really start to investigate the places where FRBs occur, and that is finally giving us the keys to understanding what they really are”, says Franz Kirsten.
More about the research
The research is published in two scientific papers in Astrophysical Journal Letters. FRB 20250316A: A brilliant and nearby one-off fast radio burst localized to 13 parsec precision by the CHIME/FRB Collaboration, with many authors including Franz Kirsten, Onsala Space Observatory, Chalmers. Link to paper: https://iopscience.iop.org/article/10.3847/2041-8213/adf62f
The other paper, James Webb Space Telescope observations of the nearby and precisely-Localized FRB 20250316A, by Peter Blanchard, Edo Berger and members of the CHIME/FRB Collaboration, is also published in Astrophysical Journal Letters. Link to paper: https://iopscience.iop.org/article/10.3847/2041-8213/adf29f
See also releases from McGill University, Center for Astrophysics | Harvard & Smithsonian, NOVA, MIT and NRAO.
Contacts
Robert Cumming, communicator, Onsala Space Observatory, Chalmers, robert.cumming@chalmers.se, +46704933114
Franz Kirsten, astronomer, Onsala Space Observatory, Chalmers, franz.kirsten@chalmers.se, +46317725532
