An international team of astronomers, including physicists from the Massachusetts Institute of Technology (MIT), has announced the detection of a fast radio burst (FRB) that is both the brightest and closest ever observed. The event, designated FRB 20250316A and nicknamed "RBFLOAT" (Radio Brightest FLash Of All Time), was detected on March 16, 2025.
Located approximately 130 million light-years away in the constellation Ursa Major, the burst's proximity and exceptional brightness offer an unprecedented opportunity to study these enigmatic cosmic phenomena. Fast radio bursts are millisecond-long flashes of radio waves, typically detected at much greater distances. The discovery was made possible by the upgraded Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope, enhanced with a network of "CHIME Outriggers" across North America, which allows for highly precise localization of FRB sources.
The precise pinpointing of FRB 20250316A has traced its origin to the spiral galaxy NGC 4141. Specifically, the burst emanated from the edge of the galaxy, just outside a star-forming region. This location suggests that the progenitor might be a more evolved magnetar—a type of neutron star with an extremely powerful magnetic field, which are considered leading candidates for the source of FRBs.
Adding to the scientific intrigue, this FRB has been identified as a "one-off" event, with no repetitions found in archival data. This characteristic contributes to the ongoing debate about whether repeating and non-repeating FRBs stem from different mechanisms. The significance of this discovery lies in its potential to unravel the mysteries surrounding FRBs, allowing scientists to study not only the burst itself but also its immediate cosmic environment in exquisite detail.