A recently discovered fast radio burst appears to pulse on a regular 16-day cycle, marking the first time that scientists have been able to see a specific tempo from any of these mysterious signals.
FRBs are bright pulses of radio emissions—lasting milliseconds, or fractions of a millisecond. In that timeframe, they can discharge as much power as hundreds of millions of Suns.
Known as FRB 180916.J0158 + 65, this fast radio burst (FRB) sends bursts of radio waves for a period of four days, stops for a period of 12 days, and then repeats itself.
The 28 initial patterns were observed for the first time between September 2018 and October 2019, according to a pre-published study. “We conclude that this is the first periodicity detected of any kind in an FRB source,” wrote the researchers in the study.
Most of them spark once, and we have never detected them again.
The FRB in question lies in a star-forming region in the outskirts of a galaxy located around 500 million light-years from Earth—making it the closest known FRB to Earth.
“The found location is radically different from the previously located repeating FRB, but also different from all previously studied FRBs,” said Kenzie Nimmo, a doctoral student at the University of Amsterdam, in a statement. “The differences between repeating and non-repeating fast radio bursts are thus less clear and we think that these events may not be linked to a particular type of galaxy or environment. It may be that FRBs are produced in a large zoo of locations across the universe and just require some specific conditions to be visible.”
“The discovery of a 16.35-day periodicity in a repeating FRB source is an important clue to the nature of this object,” the researchers wrote in their paper.
Other objects that demonstrate periodicity tend to be binary systems – stars and black holes. The period of 16.35 days could be the orbital period, the FRB object facing the Earth only during a certain part of the orbit.
Discovered in 2007, FRBs are relatively new to astronomers and their origins are mysterious. According to ScienceAlert, some of them can generate as much energy as 500 million suns in a few milliseconds.
So, the next step would be, of course, to continue staring at FRB 180916.J0158+65 for a bit. But it also would be pretty interesting to try and see if periodicity can be detected in other bursts as well.
“Future observations, both intensity and polarimetric, and at all wavebands, could distinguish among models and are strongly encouraged,” the researchers wrote, “as are searches for periodicities in other repeaters, to see if the phenomenon is generic.”