A strange radio signal has been detected in a galaxy several billion light-years from Earth, a recent study claimed.
According to the study published July 13, 2022, in Nature journal, the signal is a Fast Radio Burst (FRB), which are flashes of radio waves that typically last milliseconds.
But the new signal, which was discovered in 2019, beats for up to three seconds, about 1,000 times longer than the average.
The signal, named FRB 20191221A, followed a pattern, beating every 0.2 seconds, the scientists said in the study.
“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,” Daniele Michilli, a postdoc at MIT’s Kavli Institute for Astrophysics and Space Research, said in a statement.
“This is the first time the signal itself is periodic,” he added.
FRB 20191221A was discovered in 2019, with Michilli immediately noticing the unusual data being picked up by the Canadian Hydrogen Intensity Mapping Experiment (CHIME), located in Canada’s British Columbia.
“CHIME detects a few FRBs every day and the team typically inspects each of them within minutes,” Michilli told Down To Earth.
Michilli said the source of the bizarre FRB is not yet known. But he suspects that it could be coming from neutron stars, which are ancient remains of stars that have reached their end. The mass of these stellar bodies is about 1.4 times that of the sun.
“This FRB is periodic and not many objects produce periodic radio signals,” he said.
Alternatively, they could have come from the plasma regions of the star. We searched for evidence of ionised or star-forming regions in the direction of the FRB but could not find any, the study read.
Neutron stars emit radio waves like the beams of a lighthouse. The star’s rotation helps the signal sweep through space, which is then picked up by radio telescopes on earth, according to the European Space Agency.
Their typical period of rotation is very close to this FRB, Michilli explained. So, “neutron stars are the most plausible to explain this source,” he added.
The properties of the signal suggest that the source lives in a very turbulent environment inside its galaxy, the study speculated.
The signal was not detected again. But finding repeating FRBs could tell us how the universe is expanding, the researchers noted.
“If in the future we find numerous FRBs that repeat over time, we could use the variation of the periodicity to constrain the expansion rate of the universe, thanks to the Doppler effect,” Michilli said.
Doppler effect describes a change in the frequency of any sound or light wave produced by a moving source relative to an observer.
However, Michilli added that such studies require a very high precision. This could be possible in the future, he highlighted.