Astronomers using both space- and ground-based telescopes have detected for the first time a fast radio burst occurring inside the Milky Way, finding that it came from a magnetar, a pulsar with an extremely powerful magnetic field.

The radio component was discovered by the Canadian Hydrogen Intensity Mapping Experiment (CHIME), a radio telescope located at Dominion Radio Astrophysical Observatory in British Columbia and led by McGill University in Montreal, the University of British Columbia, and the University of Toronto.

A NASA-funded project called Survey for Transient Astronomical Radio Emission 2 (STARE2) also detected the radio burst seen by CHIME. Consisting of a trio of detectors in California and Utah and operated by Caltech and NASA’s Jet Propulsion Laboratory in Southern California, STARE 2 is led by Bochenek, Shri Kulkarni at Caltech, and Konstantin Belov at JPL. They determined the burst’s energy was comparable to FRBs.

By the time these bursts occurred, astronomers had already been monitoring their source for more than half a day.

Late on April 27, NASA’s Neil Gehrels Swift Observatory spotted a new round of activity from a magnetar called SGR 1935+2154 (SGR 1935 for short) located in the constellation Vulpecula. It was the object’s most prolific flare-up yet – a storm of rapid-fire X-ray bursts, each lasting less than a second. The storm, which raged for hours, was picked up at various times by Swift, NASA’s Fermi Gamma-ray Space Telescope, and NASA’s Neutron star Interior Composition Explorer (NICER), an X-ray telescope mounted on the International Space Station.

Later observations detected X-rays from the same source. While this does not prove that all fast radio bursts come from magnetars, it does prove that at least some do.