A Source of Mysterious Repeating Radio Signals from Space Has Been Identified
Astronomers have identified the source of mysterious repeating fast radio bursts (FRBs) from space, tracing them to a specific type of star system. The findings help narrow down the possible origins of these powerful, enigmatic signals, offering new insights into the extreme environments that produce them.
Background
- A **fast radio burst (FRB)** is an extremely intense but very brief flash of radio waves from deep space — typically lasting just milliseconds. They were first discovered in 2007, and their origins remain one of astronomy's biggest open questions.
- Most FRBs are one-off events, but a small number are **repeaters** — they flash multiple times from the same location, which makes them easier to study and trace back to a host galaxy.
- The repeating FRB in this story is **FRB 20240121A**. Scientists have now pinpointed its source: the **outskirts of a massive, mature elliptical galaxy** around 2 billion light-years away — surprisingly not a young, star-forming dwarf galaxy, where repeating FRBs were previously thought to originate.
- This matters because it challenges the leading hypothesis that repeating FRBs come from young magnetars (highly magnetic neutron stars) formed in supernova explosions. An old, "red and dead" galaxy like this one has little star formation, suggesting a different mechanism — possibly magnetars formed through other pathways like white-dwarf mergers.