TRAPPIST-1 is a red dwarf star located about 40 light years away that hosts seven Earth-sized rocky planets, with at least three orbiting in the habitable zone where liquid water could potentially exist. This makes it one of the most solar system-like exoplanet systems discovered, with TRAPPIST-1e considered among the best potentially habitable exoplanets. The system's proximity and multiple potentially habitable worlds make it an ideal target for searching for technological civilizations.
The research team conducted their search using the Five hundred meter Aperture Spherical Telescope (FAST) to exploit its unprecedented sensitivity. The observations consisted of five independent L-band pointings, each with a 20 minute integration, for a total time of 1.67 hours. The frequency coverage spanned 1.05 to 1.45GHz with a spectral resolution of ~7.5Hz allowing them to detect extremely weak radio signals that might indicate alien technology.
The team led by Guang-Yuan Song from the Dezhou University in China looked for very precise radio frequencies that slowly changed over time due to planetary motion. Such signals would be virtually impossible to produce naturally and would strongly suggest artificial origin from an advanced civilization. The study is published on the arXiv preprint server.
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