For the first time in history, astronomers have detected a flurry of fast radio bursts (FRBs) – short bursts of radio waves – coming from a single source beyond the Milky Way.

Previously FRBs have only ever been detected as one-offs, making this discovery highly significant.

While little is known about what causes FRBs, which last for just a few milliseconds, this finding will provide fresh insight into their possible origin. Others have been theorised to come from a major cosmic event that destroyed their source, such as a neutron star being engulfed by a black hole, but this multiple burst detection shows that there must be other causes for FRBs.

Scientists have been hunting for multiple bursts for some time, but the honour of discovering the first goes to Paul Scholz, a PhD student at McGill University, who on the 5th November last year was analysing results from the Puerto Rico-based Arecibo radio telescope – the largest of its kind in the world.

Using a supercomputer to sift through data collected in May and June, Scholz identified 10 bursts from the same source.

“I knew immediately that the discovery would be extremely important in the study of FRBs,” he said.

The source of these new FRBs is currently a mystery, although the researchers behind the study, which is published today in the journal Nature, are keen to stress that this is not evidence of an extra-terrestrial life form attempting to communicate. Instead, they believe they could be from a very young neutron star with an unprecedented level of power.

“The energy required to power these bursts is well beyond what we could imagine extraterrestrial life producing,” explained Scholz. “The bursts also seem to fit well with a natural explanation (i.e. a young extragalactic neutron star), so there is no reason to think that we need an explanation involving extraterrestrial life.”

It is also possible that the FRBs are the first in a new class, with causes very different to the one-offs previously detected.

“Not only did these bursts repeat, but their brightness and spectra also differ from those of other FRBs,” said Dr Laura Spitler, study first author and postdoctoral researcher at the Max Planck Institute for Radio Astronomy in Bonn, Germany.

Next the researchers plan to determine where in the universe the FRBs have come from, in a bid to learn more about their source.

They know they must have an origin beyond the Milky Way, as they have a maximum dispersion measure triple what would be expected from a source within our galaxy, but beyond that are currently unsure as to where they have originated. However, determining the galaxy of origin could take some time.

“In order to localize the source enough to identify a galaxy, we need to use radio interferometry to get a precise enough sky location,” said Scholz. “But, to do this we need to detect a burst while we are looking at the source with such a radio telescope array and, unfortunately, the source is not constantly bursting.

“So, the key is mostly patience, it may take a lot of telescope time, but eventually we should get a detection of a burst with radio interferometry, which will allow us to pinpoint the galaxy.”