A strange and persistent radio signal from a distant galaxy has been discovered by astronomers at MIT and universities in Canada and the United States. This signal appears to be flashing with a surprising degree of regularity.
The signal is categorized as a fast radio burst (FRB), which is a brief but extremely powerful burst of radio waves with an unknown astrophysical origin. However, compared to the typical FRB, this novel signal lasts up to three seconds, or 1,000 times longer. The scientists discovered radio wave bursts within this window that have a distinct periodic rhythm and reoccur every 0.2 seconds, resembling a heartbeat.
The signal, FRB 20191221A, was identified by the researchers as the longest-lasting FRB to date and having the most distinct periodic pattern.
Several billion light-years away from Earth, in a far-off galaxy, is where the signal’s source is located. Astronomers believe the signal may have come from either a radio pulsar or a magnetar, two different forms of neutron stars that are incredibly compact and fast spinning collapsed cores of big stars. However, the precise nature of that source is yet unknown.
“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.”