Astronomers have recorded a second, repeating fast radio burst that is very similar to the first. This discovery suggests that there may be many more of these cryptic signals in space. Called FRB 180814. J0422 + 73, this burst is one of 13 recently discovered fast radio bursts (or FRBs) - short and powerful radio energy signals coming from distant galaxies. For weeks, radio bursts were observed last year at the CHIME experiment in British Columbia.
The results of the latest work were revealed at the January 7 meeting of the American Astronomical Society and published in Nature on January 9.
Rapid Radio Bursts: Are Aliens Trying to Contact Us?
Most of these bursts appear once, last a few milliseconds, and no longer repeat. Therefore, astronomers puzzled over their source for years.
But then in 2016, astronomers discovered the first FRB repeat and realized that they all came from the same source FRB 121102. Astronomers tracked the signal back to their home galaxy and determined that it came from an extremely magnetic environment, such as the region surrounding a black hole. Scientists did not know if the repeating signal FRB 121102 was unique. Of the more than 60 discovered FRBs, none have been repeated - until now. Having found the second, scientists are now looking for others.
The CHIME team detected the first repetitive FRB signal on August 14 and four more in the next two months, which came from the same place in the sky. It was only during the third burst, on September 17, that scientists realized that they had a recurrence.
Calculations have shown that the new repeater is 1.6 billion light-years away. The CHIME team also saw an odd resemblance between the two famous recurring bursts. Most FRBs are just a sharp horn, like a single note played on a trumpet. But some consisted of discrete sub-bursts that varied in frequency, like wah-wah-wah on a sad trombone.
Where do fast radio bursts come from? Astronomers have many theories. At some point, they even considered the option of signals from intelligent aliens. But it is unclear whether the repetitive bursts and single bursts come from sources of the same kind, or whether single ones are repeated if observed for a long enough time.
Ilya Khel