In science fiction, it is always speculated that there are much more advanced living creatures out in the universe. Although we have never come in contact with any as we know it, they could very well know about us. Some even speculate that they are currently trying to contact us. A recent discovery by astronomers at MIT may have some insight into such a theory.
These astronomers have detected a strange and persistent radio signal from a far-off galaxy that appears to be flashing with surprising regularity. The signal is classified as a fast radio burst, or FRB -- an intensely strong burst of radio waves of unknown astrophysical origin, that typically lasts for a few milliseconds at most. However, this new signal persists for up to three seconds, about 1,000 times longer than the average FRB. It has been analyzed that it seems to be beating in a periodic pattern, described as a “heartbeat”. Researchers have officially labeled it FRB 20191221A, the longest-lasting FRB with a periodic pattern.
"There are not many things in the universe that emit strictly periodic signals," says Daniele Michilli, a postdoc at 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." The team is aiming to locate more periodic signals from the source to develop an astrophysical clock. An interesting example could be the frequency of the bursts, and how they change as the source moves away from Earth, which could be used to measure the rate at which the universe is expanding
The origin of the beat is speculated to come from a distant galaxy, several billion light-years from us. Although the source of the signal is still uncertain, many believe it originates from a radio pulsar or magnetar, both of which are neutron star types - extremely dense, rapidly spinning collapsed cores of giant stars. Radio pulsars are neutron stars that emit beams of radio waves, appearing to pulse as the star rotates, while a similar emission is produced by magnetars due to their extreme magnetic fields. The main difference between the new signal and radio emissions from our own galactic pulsars and magnetars is that FRB 20191221A appears to be more than a million times brighter.
The astronomers hope to catch additional bursts from the periodic FRB 20191221A, which can help their understanding of its source, as well as neutron stars in general. "This detection raises the question of what could cause this extreme signal that we've never seen before, and how can we use this signal to study the universe," Michilli says. "Future telescopes promise to discover thousands of FRBs a month, and at that point, we may find many more of these periodic signals."
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By: Zubin Sidhu
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References:
Massachusetts Institute of Technology. "Astronomers detect a radio 'heartbeat' billions of light-years from Earth: The clear and periodic pattern of fast radio bursts may originate from a distant neutron star." ScienceDaily. ScienceDaily, 13 July 2022. <www.sciencedaily.com/releases/2022/07/220713114600.htm>.
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