In 2007, astronomers detected the first so-called fast radio burst (FRB), which is a radio pulse lasting under a few milliseconds. Since then, many FRBs have been detected, but their origins remain poorly understood. It is commonly thought that these are produced by small and extremely energetic objects located very far away, but beyond that, there is no consensus over what these objects might be. However, a team of astrophysicists has now discovered a particular pattern of FRBs that may start shedding some insight into their origin.
These FRBs were picked up 38 times from September 2018 to February 2020, originating just outside a large galaxy 500 million light-years away. What was especially notable was the pattern in which these bursts occurred. The FRBs followed a 16-day cycle: bursts would be detected over the course of four days, then twelve days of no activity. This cycle was repeated over and over again, unlike any FRBs that have been observed before.
Although the source is still unknown, this regular pattern points to several key possibilities. The FRBs could be coming from a spinning and wobbling object, with the radio waves reaching Earth every time it faces the right direction. There could also be one object orbiting a second, emitting a burst when its orbit brings them too close together. Finally, the origin might be an orbiting object passing through a cloud of gas on its cycle, temporarily increasing its radio bursts each time. There is not yet enough evidence to decide which, if any, of these possibilities is right, but this observation is an important clue – hopefully with more to come.
Managing Correspondent: Isabella Grabski
Original Scientific Article: “Periodic activity from a fast radio burst source,” Nature.
Image Credit: “Komet” by Pepeview is licensed under CC BY-ND 2.0