A Deep SETI Search For Technosignatures In The TRAPPIST-1 System With FAST

The Five-hundred-meter Aperture Spherical Telescope (FAST) is the world’s largest single-dish radio telescope, and the search for extraterrestrial intelligence (SETI) is one of its five key science objectives.

We conducted a targeted narrowband search toward the TRAPPIST-1 system using FAST. The observations consisted of five independent L-band pointings, each with a 20-minute integration, for a total on-source time of 1.67h. The frequency coverage spanned 1.05–1.45GHz with a spectral resolution of ~7.5Hz.

We searched for narrowband drifting signals with Doppler drift rates within +_4Hz/s and a signal-to-noise ratio threshold of S/N>10 in two orthogonal linear polarizations this http URL on the system parameters adopted in this work, we estimate a minimum detectable equivalent isotropic radiated power of 2.04×10^10W, placing one of the most stringent constraints to date on persistent or high-duty-cycle narrowband transmitters in this system.

No credible technosignature candidates were identified within the searched parameter space. Nevertheless,TRAPPIST-1 remains a compelling target for future SETI efforts. We plan to extend our search to other signal types, such as periodic or transient transmitters, and to carry out broader surveys of nearby exoplanetary systems with FAST.

Guang-Yuan Song, Zhen-Zhao Tao, Bo-Lun Huang, Yan Cui, Bo Yu, Tong-Jie Zhang

Comments: 10 pages, 5 figures, Submitted to AJ
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2509.06310 [astro-ph.IM](or arXiv:2509.06310v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2509.06310
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Submission history
From: Zhenzhao Tao
[v1] Mon, 8 Sep 2025 03:23:39 UTC (1,380 KB)
https://arxiv.org/abs/2509.06310
Astrobiology