A group of astronomers from the University of Cornwell in collaboration with the Canadian Hydrogen Intensity Cartography Experiment (CHIME) has discovered a powerful radio signal from another galaxy that is repeated regularly every 16 days.
This FRB, fast radio burst, has been the first one found by astronomers that is repeated in a regular cycle following a pattern, he explains Science Alert. These signals are unpredictable, and so far, those that had been discovered did not follow any pattern, which made them difficult to study since they had no frequency.
This burst has been referred to as FRB 180916.J0158 + 65, and every 16.35 days follows a similar pattern. For four days, spit a burst or two every hour, then shut up for twelve days, and repeat the same pattern. “The discovery of this 16.35-day periodicity in a source of repeated FRB is an important clue to the nature of this object,” the researchers wrote in their article.
This frequency could be the orbital period, with the FRB object only facing the Earth during a certain part of the orbit. Nor can it be ruled out that the source is a single and solitary object, although the researchers point out that this explanation is a bit more difficult to relate to the data.
FRB 180916.J0158 + 65 is one of the few bursts of another galaxy, which is 500 million light years away, in a star-forming region. Therefore, a black hole is likely, although of stellar mass. It should then continue to look at this FRB while observing whether periodicity can be detected in other bursts.
FRBs are one of the most integral mysteries of astrophysics. They were first seen in 2007 and appear all over the sky, but the cause is unknown. Most of them explode once and are never detected again, which makes it difficult to observe them. Some spit repeated radio flares, but unpredictably. As of today, an explanation is not yet known. Astronomers observed this cycle for a total of 409 days.
To date, more than 60 FRBs have been observed. In 2015, repetitions of a source series were only found in a discovery made by the Arecibo radio telescope in Puerto Rico.