Astronomers Identify Brightest Fast Radio Burst, Pinpoint Source

A team of astronomers has detected the brightest fast radio burst (FRB) ever recorded, pinpointing its origin to a nearby galaxy. This significant discovery marks a major advancement in understanding these mysterious cosmic phenomena, which have puzzled scientists for nearly two decades. The event, designated as FRB 20250316A, occurred in March 2023 and was observed using the CHIME radio telescope located in British Columbia, Canada.

Fast radio bursts are intense flashes of radio waves that last only milliseconds yet can emit more energy in that brief time than the Sun produces in an entire year. While astronomers have identified numerous FRBs over the years, their transient nature has made it challenging to accurately determine their origins. According to Bryan Gaensler, a co-author of the study and dean of the UC Santa Cruz Science Division, “We were detecting lots of FRBs, but only had crude information on where they were occurring in the sky.” He elaborated, stating, “Now we know not only their exact address, but which room of their house they’re standing in while they’re on the call.”

RBFLOAT: A New Benchmark in Cosmic Discoveries

The recently discovered FRB, informally dubbed RBFLOAT for “Radio Brightest Flash Of All Time,” produced an extraordinary amount of energy in just a few milliseconds. The detection was made possible by the newly completed “outrigger” telescope array associated with CHIME, which spans across North America from British Columbia to West Virginia. This network significantly enhances the sensitivity required to detect such rapid and bright radio flashes.

Unlike many FRBs that repeat over time, RBFLOAT emitted all its energy in a single burst. After its initial observation, astronomers did not record any additional emissions from the same source during subsequent observations. The burst was traced to a region approximately 45 light-years across in the outskirts of a galaxy located about 130 million light-years away, specifically along one of the spiral arms where numerous star-forming regions exist.

Senior author Wen-fai Fong, a professor of physics and astronomy at Northwestern University, remarked on the discovery’s significance, noting, “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.”

Investigating the Cosmic Environment

To further understand the environment surrounding RBFLOAT, researchers utilized data from the Keck Cosmic Web Imager on the Keck II Telescope in Hawai’i. This analysis provided insights into the gaseous environment from which the FRB originated, including the density and rate of star production in that region. However, the exact cause of the flash remains uncertain.

The research team speculates that RBFLOAT may have been produced by a magnetar, a highly magnetized neutron star that remains after a supernova explosion. Co-author Yuxin Dong, a graduate student at Northwestern, noted, “Spiral arms are typically sites of ongoing star formation, which supports the idea that it came from a magnetar.” He added that the burst’s location outside the nearest star-forming clump is intriguing, suggesting the progenitor magnetar may have been displaced from its birth site.

With the CHIME Outriggers now operational, astronomers anticipate they will identify more FRBs each year. This development could lead to deeper insights into the origins of these enigmatic bursts. As Amanda Cook, a postdoctoral researcher at McGill University, stated, “This result marks a turning point. Instead of just detecting these mysterious flashes, we can now see exactly where they are coming from.” This advancement opens the possibility of discovering whether FRBs are caused by dying stars, exotic magnetic objects, or entirely new cosmic phenomena, propelling our understanding of the universe forward.