Powerful radio signal from deep in space is repeating in a ‘pattern’, say scientists

Mysterious pattern could be an important clue to the origin of mysterious blasts

A mysterious radio signal coming from deep in space appears to be repeating in a pattern, say scientists.

The powerful blast is coming from somewhere unknown and extragalactic, and is perhaps the most unusual "fast radio burst" ever detected by scientists.

Researchers have already spotted a number of the fast radio bursts originating from deep in space. They have even seen that limited numbers of them appear to repeat.

But the new breakthrough, spotted by scientists using a telescope in Canada and described in an early paper published online, is the first time that researchers have seen the blasts appearing in a regular, predictable pattern.

Astronomers have no confirmed explanation for the FRBs, with the only certain fact about their origin that they must be coming from somewhere very extreme and unusual. Proposed explanations have included everything from alien civilisations sending us messages to a star falling into a black hole, but the fact that the messages are repeating have led some scientists to lead out such cataclysmic causes.

The FRBs are in a 16-day cycle that sees them appear and then go dark, before doing the same all over again. Over the course of the cycle, the bursts will appear intensely for a four day flurry that sees a signal come every hour or more, and then it will go quiet for 12 days.

That pattern is "an important clue to the nature of this object", the researchers write in the new paper.

It appears to be coming from the edge of a massive spiral galaxy, about 500 million light years away, the researchers say. But there are few other clues about where it could be coming from or the processes that may have given rise to it.

The fact that it is repeating over a predictable period could suggest that it is coming from a binary system, since other objects in space that demonstrate similar characteristics tend to be binary systems, too. The object could be being swung around by a star or black hole, and the periodic blasts could be an indication that the object is facing us during those times, the researchers say.

It could also be possible that winds or tidal disruptions from the black hole block the signal during the periods it is silent, they note.

The repeating signals were spotted by the Canadian Hydrogen Intensity Mapping Experiment, which spends time looking for more FRBs in an attempt to find their origin. It should spend more time looking at the source of the current bursts – known as FRB 180916.J0158+65 – in an attempt to learn more about it, the researchers conclude in their paper, which is for now published on the website ArXiv before being peer reviewed and published in a journal.