Scientists have discovered an unusual fast radio burst that not only repeats, but appears to follow a repeating 16-day pattern.
According to Phys.org, FRB 180916.J0158+65 is the “first instance of a repeating FRB, which repeats in a steady cycle.” It was detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project (CHIME/FRB) from September 16, 2018 to October 30, 2019 (read the whole study over at arXiv).
“The FRB signals were observed to arrive approximately once an hour for four days and then suddenly cease—only to start up again 12 days later.”
The cause of this unusual FRB could be anything from a celestial body orbiting a star, as Phys.org suggests, to the curious result of stellar winds moving in front of whatever might be causing the bursts, resulting in a predictable pattern.
Whatever the case, astronomers have successfully determined that FRB 180916 is located in a spiral galaxy 500 million light-years away. Notably, this is only the second fast radio burst astronomers have been able to map to a specific galaxy. FRB 121102, roughly 3 billion light-years away, is the other.
There are at least 50 different theories regarding what fast radio bursts, or FRBs, actually are in general. A whole wiki is dedicated to the subject called the FRB Theory Wiki. FRBs were first discovered in 2007. Most last only milliseconds, but their signals light up detectors with a brightness that, in one case, Nature described as similar to “the power of 500 million Suns.” Only 10 or so are known to repeat.