Mysterious fast radio flashes denote a predicted object that has never been seen in space

Researchers have discovered cosmic flashes in a very surprising place in the universe. It could also point to a very surprising source.

Since FRBs were first detected in 2007, astronomers have been trying to get a grip on these puzzling phenomena. However, most of the mysterious radio bursts that have been detected have often come from so far corners of the universe that it has been difficult to pinpoint their exact cause. Even researchers suddenly at the end of 2020 We encountered fast radio bursts that appeared to be coming from our Milky Way† And now researchers have detected fast radio bursts even closer to Earth, bringing us one step closer to solving the mystery.

Rapid Radio Flashes: What Was It Again?
Rapid radio bursts are unpredictable, and they are extremely short but massive explosions in space. During these explosions, a huge amount of energy is released in a short time. Each flash lasts one thousandth of a second. However, each flash emits the same amount of energy as the sun does in a single day. The first fast radio burst was discovered in 2007. Since then, more and more fast radio bursts have been found scattered throughout the universe. Most of them are located at great distances from Earth, in galaxies billions of light years away. Only a few were observed up close.

Astronomers tracked the repeated explosions using 12 radio telescopes in the European VLBI Network (EVN) at the edge of the nearby spiral galaxy Messier 81 (M81), about 12 million light-years from Earth. Amazing discovery. Because it is the closest source of FRBs that have been located so far.

unexpected
In addition, the researchers did not expect fast radio bursts at this location. The location exactly corresponds to the location of the globular cluster, which is a dense cluster of very old stars. “It’s amazing to find fast radio bursts in a spherical mass,” researcher Franz Kirsten said. “This is a place in space where you only find old stars. Farther out in the universe, fast radio bursts are found in places where the stars are younger.”

Expected, but not noticed
What causes fast radio flashes? Scientists suspect that the flashes come from an object that has been predicted but never seen before. For example, frequent explosions can be traced back to a magnetar that formed after a white dwarf star collapsed under its own weight.

magnetic
Suspicion that fast radio bursts are caused by magnetars It has been around for a long time† A magnetar is a fairly rare type of neutron star: a highly compact remnant of massive supernovae. But the magnetar that may have caused the current radio bursts is quite unique. Many stars in groups form binary stars. Some are so close that one star attracts material from the other. Once a white dwarf captures enough extra mass from its companion, the star ends its life as a neutron star. “It’s a rare occurrence, but the easiest way to make fast radio bursts in a cluster of old stars,” said researcher Mohit Bhardwaj.

Although the study brings us one step closer to revealing the source of the fast radio bursts, it also raises new mysteries at the same time.

flickering
To the team’s surprise, some of the observed flashes were shorter than expected. “The flashes flashed in brightness within just tens of nanoseconds,” said study researcher Kenzi Nimo. “This means that it has to come from a small size in space, smaller than a football field and probably only tens of meters in diameter.”

This means that there is still much work to be done to better understand the mysterious and exotic phenomena. Future observations of M81’s globular cluster should determine, for example, whether the source is really an unusual magnetar or something else, such as an unusual pulsar or a black hole orbiting a massive star. “These rapid bursts of radio seem to give us new and unexpected insights into how stars live and die,” concludes Nemo. “Like supernovae, they can tell us more about the life path of stars in the universe.”