Scientists classified the signal in the category of so-called FRBs, or fast radio bursts. It is an intensely powerful burst of radio waves of unknown astrophysical origin that usually lasts a few milliseconds at most. But this new signal is different – it lasts sometimes up to three seconds, i.e. about a thousand times longer than the average FRB. The flashes repeat with such regularity that it reminds astronomers of the beating of a human heart.
The signal was named FRB 20191221A; it is currently the longest-lasting recurring FRB yet detected.
Unknown source
The source of the signal is located in a distant galaxy, probably several billion light years from Earth. What exactly it could be remains a mystery. Astronomers think it could originate from either a radio pulsar or a magnetar, both types of neutron stars—the extremely dense, rapidly spinning collapsed cores of giant stars.
“There aren’t many things in the universe that emit strictly periodic signals,” says Daniele Michilli of MIT. “Examples we know in our galaxy are radio pulsars and magnetars, which rotate and produce beacon-like radiation. We think this new signal could be a magnetar or a pulsar on steroids.”
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Flash hunter
Astronomers hope to detect other repeating signals from this source. The entire FRB phenomenon is new to science – this type of cosmic signal was first observed only in 2007.
Since then, devices have detected hundreds of them, but scientists still know little about them. One of the most successful instruments used for this purpose is the Canadian radio telescope CHIME (Canadian Hydrogen Intensity Mapping Experiment). This device, consisting of four large parabolic reflectors, is located at the Dominion Radio Astrophysical Observatory in British Columbia, Canada – and the scientists used it for this measurement as well.
CHIME continuously observes the sky as the Earth rotates and is designed to pick up radio waves emitted by hydrogen in the earliest stages of the universe. The telescope also happens to be sensitive to fast radio bursts, and since it began observing the sky in 2018, CHIME has picked up hundreds of FRBs emanating from different parts of the sky.
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