A team of astronomers recently detected a fast radio burst that persists about 1,000 times longer than the average burst and has a clear periodic pattern. The radio burst is an eclectic new addition to the ongoing list of mysterious radio signals that emanate from various sources across the universe.
Fast radio bursts are fleeting pulses of radio waves whose sources remain unknown. All known gusts have come from beyond the Milky Way to 2020when the CHIME radio telescope discovered a signal that seemed to come from our galactic neighborhood.
The recently reported fast radio burst – detected in December 2019 and named FRB 20191221A – came from a source billions of light-years away and was also observed by CHIME. Unlike most fast radio bursts, which last a few milliseconds, the recent burst lasted three seconds. Signal analysis by a research team was published this week in Nature.
“Not only was it very long…but there were periodic spikes that were remarkably precise, emitting every fraction of a second – boom, boom, boom – like a heartbeat,” said MIT astrophysicist Daniele Michilli. and co-author of the study, in an institute Release. “This is the first time that the signal itself is periodic.”
Based on the periodicity of the burst, the researchers believe it originated from a distant neutron star. Neutron stars are the collapsed remnants of dead stars and are among the densest objects in the universe.
Some spinning neutron stars have very strong magnetic fields and are called pulsars or magnetars, depending on the intensity of these fields. When stars rotate rapidly, they emit electromagnetic radiation, which arrives at Earth in the form of radio waves.
The pulsars are useful for studying gravitational waves because their reliable light pulses come from their poles and can be timed with extreme precision. Scientists use differences in pulsar timing to determine if the fabric of spacetime has been warped.
Fast radio bursts are often chalked to the activity of these extreme objects. While FRB 20191221A is no exception to this rule, it is odd even by fast radio burst standards due to its consistency.
“There aren’t many things in the universe that emit strictly periodic signals,” Michilli said. “Examples we know of in our own galaxy are radio pulsars and magnetars, which spin and produce a lighthouse-like radiated emission. And we think this new signal could be a magnetar or a pulsar on steroids.
Hopefully, FRB 20191221A will remain more consistent than its enigmatic brethren. In October 2021, another team of astronomers signaled a radio signal which appeared to be corkscrewing towards Earth from the center of the Milky Way, but when they formed more instruments at the source, it became silent.
David Kaplan, co-author of that paper and an astrophysicist at the University of Wisconsin-Milwaukee, told Gizmodo at the time that sometimes magnetic fields can become tangled, causing an otherwise coherent pulse of radio signals to become intermittent. where to go completely silent.
According to the MIT release, FRB 20191221A appears to be more than a million times brighter than radio emissions from pulsars and magnetars in the Milky Way. If the radio source continues to have bursts, the team may be able to better understand the origins of the enigmatic bursts.
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