In a bizarre new discovery, astronomers have detected a mysterious, repeating fast radio burst emanating from a dwarf galaxy located 3 billion light-years away.
Astronomers detected the object, named FRB 190520, when it released a burst of radio waves on May 20, 2019. The researchers used the Five-hundred-meter Aperture Spherical radio Telescope, or FAST, in China, and discovered the burst in the telescope data in November 2019. When they conducted follow-up observations, the astronomers noticed something unusual — the object was releasing frequent, repeating bursts of radio waves.
Fast radio bursts, or FRBs, are millisecond-long bursts of radio waves in space. Individual radio bursts emit once and don’t repeat. But repeating fast radio bursts are known to send out short, energetic radio waves multiple times.
In 2020, the team used the National Science Foundation’s Karl G. Jansky Very Large Array, or VLA, of telescopes to pinpoint the origin of the burst before zeroing in on it using the Subaru Telescope in Hawaii. Subaru’s observations in visible light showed that the burst came from the outskirts of a distant dwarf galaxy.
Currently, less than 5% of the hundreds of identified fast radio bursts have been known to repeat and only a few of them are regularly active.
But FRB 190520 is the only persistently active one, meaning that it has never “turned off” since being discovered, said study author Di Li, chief scientist for the radio division of the National Astronomical Observatories of China and the FAST Operation Center. Meanwhile, FRB 121102, “the first known famous repeater, can turn off for months,” Li said.