Last week we ran a story on how Fast Radio Bursts (FRBs) had been, at least in the case of four of these super energetic events, localized to the outskirts of galaxies. Today, we get word from Jodrell Bank that across four years of observations they have discovered a really weird repeating pattern of behavior in FRB 121102. This pattern could only be discovered thanks to regular monitoring by the giant, 76-meter Lovell Telescope. Over these many years, they found this object will go quiet for roughly 67 days at a time, and then become active, with irregular bursts of radio emission scattered through a ninety-day window. The randomness of the outbursts in that window is something we’re not used to seeing in astronomy, but this kind of behavior is seen in another FRB, FRB 180916.JU10158+56. While the latter has a significantly longer designation, its outburst cycle is ten times shorter than that of 121102. 

It’s still not clear what these objects are, but this kind of burst behavior is consistent with the outbursts being tied to some sort of an orbital pattern and a high-mass or extreme object. This work, however, seems to maybe rule out as a cause of magnetic precession. Since magnetic fields aren’t well understood, we want to leave that possibility on the table for now but push it out to the edge of our lists of possible theories. 

More Information

The University of Manchester press release 

“Possible periodic activity in the repeating FRB 121102,” Kaustubh Rajwade et al., 2020 May 19, Monthly Notices of the Royal Astronomical Society (Preprint on arxiv.org)