Mysterious fast radio bursts in space are getting weirder

(CNN) — Fast radio bursts, or bright, millisecond flashes of radio waves in space, are one of the universe’s most enduring mysteries, and they’re just getting a little weird.

The first fast radio burst, or FRB, was detected in 2007, and since then hundreds of these fast and intense events have been detected from distant points across the universe. In a millisecond, explosions can generate as much energy as the Sun produces in a year or more. According to previous research.

But astronomers don’t understand what causes it.

Now, scientists have observed a strange, never-before-seen pattern in a recurring fast radio burst called FRB 20220912A. A study published Wednesday in the journal Monthly Notices of the Royal Astronomical Society Details of the discovery, which provides valuable clues to researchers trying to determine the source of this phenomenon, while presenting new mysteries to unravel.

Astronomers detected the explosion using the California-based SETI Institute’s Allen Telescope Array, or ATA, which includes 42 antennas at the Hat Creek Radio Observatory in the Cascade Mountains.

The team detected 35 fast radio pulses coming from the same source over a period of two months.

Many fast radio bursts emit radio waves that last for a few milliseconds at most before disappearing, making them difficult to observe. but, It is known that some radio bursts are repeated They emit follow-up bursts, which allowed astronomers to track the signals To distant galaxies.

At first, FRB 20220912A appeared similar to other known “repeaters,” with each detected burst moving from higher to lower frequencies.

But closer examination of the signal revealed something new: a noticeable drop in the central frequency of the explosions, which was like a celestial whistle.

The decrease became more pronounced when the researchers converted the signals into sounds using xylophone tones. The high notes correspond to the beginning of the beat, while the low notes act as the ending note.

The team tried to determine if there was a pattern in the times between each burst, similar to known fast, repetitive radio bursts. But researchers And they couldn’t discover any of it In the case of FRB 20220912A, suggesting that celestial phenomena can also be unpredictable.

“This work is exciting because it confirms known properties of fast radio bursts and discovers new ones,” said Dr. Sofia Shaikh, lead author of the study and a postdoctoral fellow, in a statement. MPS-Ascending From the National Science Foundation’s SETI Institute.

More questions than answers

According to the researchers, each observation of fast radio bursts provides more information and more questions.

Astronomers suspect that some fast radio bursts may come from it Magnetic starsThe strongly magnetized cores of dead stars. But other research has suggested that collisions between dense neutron stars or dead stars called white dwarfs could be to blame.

“We are working to narrow down the origin of fast radio bursts to extreme objects such as magnetars, but no existing model can explain all the properties observed so far,” says Sheikh.

This study was the first to detect fast radio bursts using the Allen Telescope array, which has been under renovation in recent years. Continued upgrades of the array will not only allow astronomers to follow the behavior of fast radio bursts at different frequencies, but will also allow them to search for weaker signals.

“This work demonstrates that new telescopes with unique capabilities, such as ATA, can provide a new perspective on the remaining mysteries in the science of fast radio bursts,” says Sheikh.