A fast radio burst, or a strong pulse of energy, was tracked to a distant long-dead galaxy that astronomers never thought could produce such a signal.

Astronomer Calvin Leung was excited last summer to crunch data from a newly commissioned radio telescope to precisely pinpoint the origin of repeated bursts of intense radio waves—so-called fast radio bursts (FRBs)—emanating from somewhere in the northern constellation Ursa Minor.

Astronomers have traced two mysterious fast radio bursts from space to wildly different places, which suggests the phenomenon may originate in diverse ways.

In February 2024, scientists on Earth detected a powerful radio blast from outer space. Seeking to discover where it had come from, they traced the brief flash of energy back to its extraterrestrial source—and discovered something unexpected.

Astronomers have observed over a thousand of them to date; some come from sources that repeatedly emit FRBs, while others seem to burst once and go silent. You can produce this sort of sudden surge of energy by destroying something.

Instead of finding the radio burst in a region of young stars, researchers traced its origin to the outskirts of a “dead” elliptical galaxy.

For the first time, astronomers have traced a fast radio burst (FRB) to the outskirts of an ancient, dead, elliptical galaxy—an unprecedented home for a phenomenon previously associated with much younger galaxies.

Large stars have cosmically short lifetimes, so the fact that this FRB occurred in an old, long-dead galaxy means that the neutron star that generated it must also be old.

Fast radio bursts (FRBs) are mysterious pulses of energy that can last from a fraction of a millisecond to about three seconds. Most of them come from outside the galaxy, although one has been detected coming from a source inside the Milky Way.