FRBs: Brightest-ever Mystery Radio Burst Signal Spotted In Space

3_13_Parkes Observatory
The three signals were spotted at the Parkes Observatory. Amanda Slater/Flickr

Updated | Scientists have spotted three new fast radio bursts (FRBs) in less than two weeks—and one is the brightest ever observed.

FRBs are mysterious signals that appear to come from deep space. Twinkling for just milliseconds, their sources are, as yet, unknown.

Astronomers use the world's largest radio telescopes to detect the weak, elusive flashes. But even these capture relatively small slivers of sky, so astronomers have to be lucky to catch the bursts. So far, just 33 have been spotted since the first in 2001.

The three latest bursts were spied on March 1, March 9 and March 11 using the Parkes Observatory in Australia, according to the FRB Catalogue. They were recorded in the Astronomer's Telegram.

Finding three FRBs in such quick succession is very unusual, Emily Petroff, an astrophysicist behind the catalogue, told Newsweek. "The Parkes telescope is the premiere FRB-finder in the world, but it still only finds 5 or 6 FRBs per year, on average. So finding three in a week is particularly incredible," she said.

Alien life or astrophysics?

The Breakthrough Listen project spotted the March 1 FRB while hunting for intelligent alien life. "BL is foremostly a search for technologically-capable life beyond Earth; however, a real-time search for FRBs runs in tandem," the team wrote in the Telegram.

Danny Price of the Berkeley SETI Research Center (BSRC) and one of the astronomers behind the March 1 spot wrote in a blog post that, while the team would love aliens to be behind the signals, they need to "rule out all plausible astrophysical theories first."

Vishal Gajjar, an astrophysicist at BSRC told Newsweek that he did not personally believe known FRBs were alien communication attempts because they "occur all over the sky and show similar properties."

Something like FRBs, but modified to communicate their artificial origin, he said, would be a better way for ET to get in touch.

Extremely bright FRB

Last Friday (March 9), saw the brightest FRB ever observed. It had the "highest signal-to-noise ratio" ever recorded, researcher Stefan Oslowski of the Swinburne University of Technology in Melbourne, Australia wrote in a tweet. Oslowski and colleagues also recorded the March 11 FRB, which occurred within 50 hours of March 9's.

The Parkes Pulsar Timing Array just discovered the highest signal-to-noise ratio Fast Radio Burst ever! via @astronomerstel @frbcatalogue

— Stefan Oslowski (@StefanOslowski) March 9, 2018

The brightness of this FRB, Petroff said, could help scientists narrow down its cause. "We may learn more from this burst about what types of theories can and cannot explain such extreme emission," she explained.

Unknown source

Although their sources remain unknown, scientists are learning more about FRBs all the time. One of the signals has been found to repeat, which has let scientists take a deeper look at the evasive bursts.

Earlier this year, researchers reported the flashing signal might be caused by a neutron star sitting in an extreme environment like a powerful nebula or the remains of a supernova.

"Right now there are dozens of theories trying to explain the fast radio burst phenomenon. It's also possible that multiple...theories are correct and that fast radio bursts can originate from a number of different circumstances," astronomer Jason Hessels from the Netherlands Institute for Radio Astronomy, told Newsweek. Hessels was not involved in the three Astronomy Telegram FRB reports.

Some astronomers predict that all FRBs repeat, but most of their flashes are just too dim to see. Maura McLaughlin, an astronomer from West Virginia University in Morgantown, thinks the March 9 signal could be a promising target for further bursts, New Scientist reports. She said: "If we believe that all FRBs repeat and it's just a matter of waiting long enough for one to be bright enough, we should be able to detect more pulses from this one because it's so bright."

McLaughlin thinks far more FRB discoveries are on the cards. "Everyone's sort of jumping on this bandwagon of looking for FRBs in the background all the time no matter what else is going on," she said. "This should lead to a huge uptick in detections in the next year or so."

Explaining the appeal of FRBs, Hessels said: "It doesn't happen very often that astronomers discover a new type of phenomenon like this, and it's really fun to try and solve this mystery."

If researchers are lucky, he added, FRBs might serve as useful tools to shed light on other space mysteries as well.

This article has been updated to include comment from Jason Hessels, Vishal Gajjar and Emily Petroff.