China's Sky Eye Reveals Fast Radio Bursts Come From Pairs

For nearly two decades, astronomers have been chasing one of space's biggest mysteries: what causes the incredibly powerful flashes of radio waves that zip across the universe in milliseconds?

Now, a team including researchers from The University of Hong Kong has their answer. Using China's Five-hundred-meter Aperture Spherical Telescope (nicknamed "China Sky Eye"), they discovered that at least some of these cosmic flashes come from binary star systems, not isolated stars as scientists previously thought.

The breakthrough came after 20 months of patient observation. The team monitored a repeating fast radio burst located 2.5 billion light-years away, watching and waiting for something unusual to happen.

Then in late 2023, they spotted it: a dramatic change in the radio signal's polarization properties. The signal shifted suddenly by more than a hundred times its normal level, then returned to normal over two weeks.

Professor Bing Zhang, Chair Professor of Astrophysics at HKU, explains what likely happened. A companion star ejected a cloud of magnetized plasma (similar to solar flares from our sun), which briefly crossed between Earth and the radio burst source.

The discovery points to a binary system containing a magnetar (a neutron star with an extremely powerful magnetic field) paired with a star similar to our sun. Though the companion star can't be directly observed at such distances, its fingerprints are all over the radio signal.

Why This Inspires

This discovery represents years of dedicated observation paying off in a single moment of clarity. The team's perseverance transformed what initially seemed like an "unremarkable" radio source into a window onto how binary star systems work across vast cosmic distances.

The findings also support recent theories that all fast radio bursts might originate from magnetars, with binary companions creating the perfect conditions for repeated bursts. It's a reminder that the universe's most mysterious phenomena often have elegant explanations waiting to be discovered.

The research appears in Science, one of the world's most prestigious scientific journals. The team used both China's FAST telescope and Australia's Parkes telescope to confirm their observations.

As astronomers continue monitoring other repeating radio bursts, they'll learn how common these binary systems actually are. Each discovery brings us closer to understanding the violent, energetic processes that light up the cosmos billions of light-years away.