Scientists detect mysterious radio signal from star system 238 light-years away
Scientists have detected a mysterious radio signal while searching for extraterrestrial technology. This narrowband radio signal, designated NBS 260108, was detected by a Chinese-led research team. The testing new software on archived data collected in 2021 by China’s FAST telescope.
The team found that the signal appeared in observations made while FAST was pointed toward K2-155, a star system located approximately 238 light-years from Earth. The K2-155 star system has three known planets that are larger than Earth but smaller than ice giants like Neptune.
Characteristics of the Signal
The signal appeared as a radio tone concentrated within a very narrow band of frequencies. This narrow bandwidth matters because natural cosmic phenomena rarely produce such signals, whereas artificial transmitters are able to produce them. The research team also found that the signal’s frequency gradually decreased over time. This frequency drift is consistent with the kind of frequency shift that can occur when a transmitter and receiver move relative to one another.
FAST uses a receiver that monitors 19 beams at once. The signal caught the team’s attention because it appeared in the single beam pointed directly at K2-155. The researchers found no trace of it in the other 18 beams. The team also noticed an unusual feature when it compared the receiver’s two polarization channels. It appeared on the “YY” channel. Its signal-to-noise ratio was about 23 in that channel, but the researchers found no corresponding signal in the “XX” channel.
