By Tim Binnall
Astronomers have found a new clue in the quest to solve the riddle of fast radio bursts (FRBs) in the form of a repeating pulse which boasts a curious pattern. The fleeting bursts of energy have become something of a cause celebre in scientific circles over the past few years as an increasing number of the inexplicable pulses have been detected. For understandable reasons, rarely discovered repeating fast radio bursts are believed to be the best sources for possible insight into what may be behind the phenomenon.
A new study examining one such recurring pulse, dubbed FRB 121102, has reportedly determined that it follows an intriguing 157-day cycle wherein it is active for approximately 90 days and then is dormant for the other 60 days. In a testament to just how much time and effort has been invested in the fast radio burst mystery, the pattern was found following a whopping five years of observing the pulse. The discovery of the cycle comes on the heels of a similar breakthrough earlier this year when astronomers found that a different repeating FRB followed a relatively short 16-day cycle.
The vastly different length between the two known patterns, which are the only cycles discovered to date, seemingly only compounds the confusion surrounding the phenomenon. Conceding that "this exciting discovery highlights how little we know about the origin of FRBs," researcher Duncan Lorimer mused that it is still rather helpful since continued observation of these pulses and detection of additional heretofore-unseen patterns may ultimately be what provides an answer as to their source.