Chinese astronomers utilized the FAST radio telescope, featuring a 500-meter aperture, to monitor 33 exoplanetary systems for potential extraterrestrial radio signals. Researchers specifically look for narrow-band signals, which differ from the broader frequency ranges typically emitted by natural cosmic sources.
A signal designated as NBS 260108 was detected originating from the direction of the K2-155 system, located 238 light-years from Earth. This signal, recorded at a frequency of 1140.604 MHz, exhibited characteristics of an artificial source, including narrow-band properties and Doppler shifting.
To filter out terrestrial interference, the team employed a multibeam coincidence matching method using the telescope's 19-beam receiver. While the signal passed this initial test, subsequent analysis of its polarization revealed inconsistencies that cast doubt on an extraterrestrial origin.
The researchers concluded there is no evidence to suggest the signal is a message from an alien civilization. The study served primarily as a practical test for refining techniques used to identify and eliminate radio interference in future deep space observations.
