Summary:
- Astronomers have discovered the source of a mysterious repeating radio signal that was detected in space, known as FRB 20191221A.
- The signal was found to be coming from a magnetar, a type of neutron star with an extremely powerful magnetic field, located about 21,000 light-years from Earth.
- This discovery provides important insights into the nature of fast radio bursts (FRBs), which are brief, intense bursts of radio waves from distant sources in the universe, and helps explain the repeating pattern of this particular FRB.