Astronomers discovered a radio signal that flashes every three seconds from a distant galaxy.
Over a billion light-years distant, the signal is called FRB 20191221A and it’s classed as a “fast radio burst”—a radio pulse. FRB 20191221A has a life expectancy of around 1,000 times that of most FRBs. It is the longest-lasting, most consistent radio signal in all the night sky.
Scientists think that the radio signal may be coming from a neutron star—what remains of the collapsed core of a giant star after it’s exploded as a supernova. Neutron stars spin rapidly.
Though the origin of FRBs are mysterious it’s hoped that each one’s frequency, and how they differ in distance from us, could tell scientists about the exact rate at which the universe is expanding. The first FRB (Found in 2007) was discovered.
FRB 20191221A first became apparent on December 21, 2019. “It was unusual,” said Daniele Michilli, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research. “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.”
What is the source of FRB 20191221A then?
“There are not many things in the universe that emit strictly periodic signals,” said Michilli. “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.”
Types and types of neutron stars. A pulsar emits radio waves, appears to pulse when the star rotates. A magnetar however has very strong magnetic fields. FRB 20191221A’s signal is more bright than magnetars and pulsars in the Milky Way.
“From the properties of this new signal, we can say that around this source, there’s a cloud of plasma that must be extremely turbulent,” said Michilli. “Future telescopes promise to discover thousands of FRBs a month, and at that point we may find many more of these periodic signals.”
I wish you clear skies, and big eyes.