The source of the strange repeating pulses of radio emission from Fast Radio Burst 121102, observed in new detail earlier this year by the Breakthrough Listen science team at Berkeley SETI Research Center, remains something of a mystery. However, results reported today in the journal Nature are shedding more light on the object. Green Bank Telescope observations, using the Breakthrough Listen backend instrument, have revealed that the radio emission is almost entirely linearly polarized. This suggests that the source of the bursts is embedded in a powerful magnetic field, perhaps from a nearby massive black hole. It's unlikely that the bursts are a signature of extraterrestrial technology, however. They are most likely coming from a magnetar - the incredibly dense, highly magnetized remains of a star that has burned up all of its fuel. Nevertheless, FRB 121102 remains an intriguing object that has yet to give up all of its secrets.
A new article about this appears in Nature.