Astronomers have recently discovered a mysterious radio signal in space with a pattern similar to that of a “heartbeat.” According to a study published in the scientific journal Nature, the signal came from a galaxy about 1 billion light-years away, but the exact location and cause of the outburst are unknown.
Fast radio bursts (FRBs) are high-intensity, millisecond-long bursts of radio waves whose origin is unknown, CNN reported. The first FRB was discovered in 2007, and hundreds of similar cosmic flashes have been detected since then.
The report pointed out that because of the fast and unpredictable nature of fast radio bursts, it is difficult to observe. Many FRBs release ultrabright radio waves that last for at most a few milliseconds before disappearing completely, with about 10% of them being observed to be repeating and patterned.
Daniele Michilli, a researcher in astrophysics at the Massachusetts Institute of Technology, said their previous observation of a phenomenon “quirky in every way” immediately caught everyone’s attention. He said he monitored data from large radio telescopes in 2019 and received the longest-lasting fast radio burst to date.
The signal, named FRB “20191221A”, lasted as long as 3 seconds, about 1,000 times longer than a typical fast radio burst.
“It’s very unusual, it’s not only very long, about three seconds, but there are very precise periodic spikes, every second making a plop, plop, like a heartbeat,” Midgley noted. This is the first periodic signal observed.”
“The signal is formed by a series of consecutive peaks, and we found that they are separated by about 0.2 seconds,” he said in an interview.
Midgley said the team doesn’t yet know the exact galaxy where the outburst originated, and even distance estimates of a billion light-years are “highly uncertain,” but the signal does contain clues about where it came from and what might be causing its idiosyncratic nature.
When the researchers analyzed FRB 20191221A, the signal was similar to that released by two different types of neutron stars, or the dense remnants of the death of giant stars, called radio pulsars and magnetars.
Magnetars are neutron stars with incredibly strong magnetic fields, and radio pulsars emit radio waves that appear to pulse as the neutron star rotates. Both stellar objects produce a signal similar to the twinkling beam of a lighthouse.
The research team will try to obtain more signals from this radio pulse, as well as other signals with similar periodic properties. The frequencies of radio waves and how they change can be used to help astronomers understand how fast the universe is expanding.
“This discovery raises the question of what causes this unusual signal that we haven’t seen before, and how we can use it to study the universe,” Midgley said. “Future telescopes are expected to detect thousands of FRBs each month, and we may find more of these periodic signals by then.”