As the name suggests, Fast Radio Bursts (FRBs) are short-lived – but powerful – pulses of radio waves from the cosmos.

Their brevity, combined with the fact that it’s difficult to pinpoint their location, have ensured their origins remain enigmatic.

Outlining their work at a major conference, astronomers say they have now traced the source of one of these bursts to a different galaxy.

It’s an important step to finally solving the mystery, which has spawned a variety of different possible explanations, from black holes to extra-terrestrial intelligence.

The first FRB was discovered in 2007, in archived data from the Parkes Radio Telescope in Australia. Astronomers were searching for new examples of magnetised neutron stars called pulsars, but found a new phenomenon – a radio burst from 2001. Since then, 18 FRBs – also referred to as “flashes” or “sizzles” – have been found in total.

“I don’t exaggerate when I say there are more theories for what these could be than there are observed bursts,” first author of the new study, Shami Chatterjee, told the BBC’s Science in Action programme.

All FRBs were found using single-dish radio telescopes that are unable to narrow down the sources’ locations with enough precision to further characterise the flashes.

But Dr Chatterjee, from Cornell University in Ithaca, New York, and colleagues used a multi-antenna radio telescope called the Karl G Jansky Very Large Array (VLA) in New Mexico, which had sufficient resolution to precisely determine the location of a flash known as FRB 121102.

Unlike all the others, this FRB – discovered in 2012 – has recurred several times.

“When we reported last year that one of these objects was repeating, that – in one go – knocked out about half of those models, because for this one source, at least, we knew it couldn’t be explosive. It had to be something where the engine that produced this survived for the next flash.”

In 83 hours of observing time over six months in 2016, the VLA detected nine bursts from FRB 121102.

“We now know that this particular burst comes from a dwarf galaxy more than three billion light-years from Earth,” said Dr Chatterjee. That’s a staggering distance from Earth, underlining just how energetic these flashes are.

“That simple fact is a huge advance in our understanding of these events.”

The team has published their findings in Nature journal and has outlined them at the 229th American Astronomical Society (AAS) meeting in Grapevine, Texas.

Since this is the only known repeating burst, it’s possible it could represent a completely different phenomenon to other FRBs.

In addition to detecting the bright bursts from FRB 121102, the team’s observations also revealed an ongoing, persistent source of weaker radio emission in the same region.

The flashes and the persistent source must be within 100 light-years of each other, and scientists think they are likely to be either the same object or physically associated with one another.