News Astronomy

A fast radio burst’s unlikely source may be a cluster of old stars

Its origin challenges assumptions about what causes these enigmatic signals

illustration of galaxy M81 next to a cluster of old stars

A cluster of old stars orbiting the galaxy M81 (illustrated) is home to an enigmatic source of repeating blasts of radio waves, challenging theories about what causes such bursts.

Danielle Futselaar/ASTRON

By Mara Johnson-Groh

In a galaxy not so far away, astronomers have located a surprising source of a mysterious, rapid radio signal.

The signal, a repeating fast radio burst, or FRB, was observed over several months in 2021, allowing astronomers to pinpoint its location to a globular cluster — a tight, spherical cluster of stars — in M81, a massive spiral galaxy 12 million light-years away.