A mysterious radio source located in a galaxy 500 million light years from Earth is pulsing on a 16-day cycle, like clockwork, according to a new study. This marks the first time that scientists have ever detected periodicity in these signals, which are known as fast radio bursts (FRBs), and is a major step toward unmasking their sources.
Pulses from these repeat bursts have, so far, seemed somewhat random and discordant in their timing. But that changed last year, when the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project (CHIME/FRB), a group dedicated to observing and studying FRBs, discovered that a repeater called FRB 180916.J0158+65 had a regular cadence.
The CHIME/FRB team kept tabs on the repeating burst between September 2018 and October 2019 using the CHIME radio telescope in British Columbia. During that period, the bursts were clustered into a period of four days, and then seemed to switch off for the next 12 days, for a total cycle of about 16 days. Some cycles did not produce any visible bursts, but those that did were all synced up to the same 16-day intervals.