MIT astronomers find ‘strange’ radio signal from distant galaxy

The CHIME Telescope, located at the Dominion Radio Astrophysical Observatory in Canada.

Astronomers at MIT and other universities in Canada and USA have detected a “strange and persistent radio signal” from a distant galaxy – the most regular and long-lasting signal found in the night sky till date.

According to MIT, the signal is classified as an FRB or fast radio burst, which is “an intensely strong burst of radio waves of unknown astrophysical origin.” The average FRB will typically last a few milliseconds, but what makes this one unique is that it persists for up to 3 seconds – an unusually long time for an FRB.

“Within this window, the team detected bursts of radio waves that repeat every 0.2 seconds in a clear periodic pattern, similar to a beating heart,” read MIT’s press release.

Where does this radio signal originate? Scientists know it’s coming from a galaxy billions of light-years away from earth, but its exact origin remains a mystery. The signal, dubbed signal FRB 20191221A, is probably emanating from a neutron star — which is an extremely dense, rapidly spinning collapsed core of a giant star.

“There are not many things in the universe that emit strictly periodic signals,” says Daniele Michilli, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research. “Examples that we know of in our own galaxy are radio pulsars and magnetars, which rotate and produce a beamed emission similar to a lighthouse. And we think this new signal could be a magnetar or pulsar on steroids.”

Radio pulsars and magnetars are both types of neutron stars.

The signal was detected by the Canadian Hydrogen Intensity Mapping Experiment, or CHIME, a large radio telescope located in Canada. Michilli noticed the strangely persistent FRB while looking at CHIME data in December 2019.

“It was unusual,” he said, according to MIT. “Not only was it very long, lasting about three seconds, but there were periodic peaks that were remarkably precise, emitting every fraction of a second — boom, boom, boom — like a heartbeat. This is the first time the signal itself is periodic.”

Scientists are hoping this discovery will help them figure out the rate at which the universe is expanding.