What are fast radio bursts?

Fast radio bursts (FRBs) are millisecond-duration radio pulses of extragalactic origin first detected in 2007. Thousands have now been catalogued, some repeating, but their physical origin remains disputed.

Magnetars (highly magnetised neutron stars) are the leading candidate, supported by the 2020 detection of an FRB from the Galactic magnetar SGR 1935+2154. Whether all FRBs share this origin is still open.