Decades-long Mystery: Space Signal Blinking Every 20 Minutes Since 1988

Astronomers have discovered a new object in space, named GPM J1839–10, that emits regular bursts of radio energy every 21 minutes, which is much slower than typical pulsars. The object was found during a search for transient objects and has been emitting signals since 1988. The nature of this phenomenon remains a mystery, as it does not fit into any known category of objects that can produce such behavior.