Most Extreme Fast Radio Burst Yet Deepens the Mystery of Signals From Deep Space
- Finalist for the Nesta Tipping Point prize and a degree in broadcast journalism from the University of Missouri-Columbia.
Artist's conception of a neutron star with an ultra-strong magnetic field, called a magnetar, emitting radio waves (red).
What's happening
Researchers have discovered the most remarkable example of a so-called fast radio burst from the other side of the universe.
Why it matters
FRBs provide insights into some of the most powerful objects in deep space and have only been known for the past 15 years.
Scientists have identified the most extreme example of one of the universe's newer mysteries.
Fast radio bursts are powerful but fleeting bursts of radio waves emanating from tumultuous sources in deep space. Over 95% of FRBs discovered so far have been detected just once and then never heard from again. But a small amount repeat, allowing astronomers to get a better sense of their source.
Now an international team of researchers led by Li Di from the National Astronomical Observatories of the Chinese Academy of Sciences has found FRB 190520B, which not only repeats, but is paired with a second mysterious source of weaker radio waves that can be picked up between the more powerful bursts. It's a loud signal and background noise all in one package.
Only one other FRB has these characteristics -- FRB 121102A, which was the first repeater ever found. However, FRB 190520B is more active.
"Now we have two like this, and that brings up some important questions," said CalTech's Casey Law, who is a member of the team and co-author of a paper laying out the discovery this week in the journal Nature, in a statement.
One of those questions is whether all FRBs are basically the same... or not.
"Are those that repeat different from those that don't? What about the persistent radio emission — is that common?" said Kshitij Aggarwal, a graduate student at West Virginia University and member of the team.
Astronomers have begun to use FRBs as tools to study the material in space that the signals travel through to reach Earth. The signals even helped to unravel the universe's "missing matter" problem. But this didn't work in the case of FRB 190520B, likely because of an unusual amount of dust and material in the galaxy it originates from.
This throws doubt on the entire practice of using FRBs as a sort of cosmic measuring stick and leads the researchers to speculate that FRB 190520B may actually be a "newborn" repeater. That means it's coming from a source still surrounded by dense material thrown off from a supernova explosion that left behind an extremely energetic neutron star. Neutron stars or pulsars are thought to be the likely sources of most FRBs.
The weird nature of the new repeater also suggests that FRB behavior may evolve and change as the bursts age. Most of all it makes it clear there's still plenty to learn about the phenomenon, which has only been known to astronomers for the past 15 years.
"The FRB field is moving very fast right now, and new discoveries are coming out monthly," said West Virginia University's Sarah Burke-Spolaor. "However, big questions still remain, and this object is giving us challenging clues about those questions."