A team of astronomers, including researchers from MIT, have detected a repeating rhythm of fast radio bursts that are emanating from an unknown source outside of our galaxy. The source of the radio bursts is 500 million light-years away. Fast radio bursts, also known as FRBs, are short, intense flashes of radio waves that are thought to be the product of small, distant, and extremely dense objects.
Exactly what creates the FRBs is a mystery for astrophysicists. Typically an FRB lasts only a few milliseconds, but during that short period, they can outshine entire galaxies. Scientists say that, for the most part, an FRB is a one-off flashing briefly before disappearing entirely. In a handful of instances, astronomers have observed fast radio bursts multiple times from the same source, but they’ve had no discernible pattern.
The new FRB source was cataloged by the researchers as FRB 180916.J0158+65 and is the first to produce a periodic or cyclical pattern of fast radio bursts. The pattern begins with a “noisy, four-day window” where the source emits random bursts of radio waves followed by a 12-day period of silence. The researchers have observed the 16-day pattern of fast radio bursts recurring consistently over 500 days of observations.
The team says that the FRB is reporting “like clockwork.” The researchers say that the pattern is a big clue that can be used to hunt down the physics of what causes the bright flashes, which no one currently understands. The FRB source was observed using the CHIME antenna array that has no moving parts. CHIME picked up 38 FRBs from the single source between September 2000 February 18, 2020.
The researchers say that the bursts are something never seen before marking a new phenomenon in astrophysics. The pattern the researchers discovered is being created by an unknown process. Still, the team believes one possibility is that the signals are coming from a single compact object such as a neutron star that’s spinning and wobbling.
If the object is spinning along an axis and that axis is only pointed at the Earth every four of 16 days, periodic radio bursts would be observed. A binary star system is a possibility, as is a radio-emitting source that circles the central star. The team also admits that the signals could be from something out as a magnetar, which is a type of neutron star believed to have an extremely powerful magnetic field.