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Dual-Backend Multibeam Position Switching Targeted SETI Observations toward Nearby Active Planet-Hosting Systems with FAST

Jian-Kang Li, Zhen-Zhao Tao, Pei Wang, Tong-Jie Zhang

TL;DR

This work applies FAST's high sensitivity to a targeted SETI survey of nearby planet-hosting systems, integrating multibeam position switching with dual backends to search for technosignatures in the 1.05–1.45 GHz band. The dual-backend approach enables complementary analyses of narrowband drifting signals and channel-width periodic signals, with rigorous RFI mitigation through multibeam calibration. No credible technosignatures were detected, allowing 95% confidence upper limits: narrowband transmitters with EIRP above $3.98\times10^{8}$ W and periodic transmitters with EIRP above $1.80\times10^{10}$ W within the observed band. The study demonstrates an efficient, robust SETI methodology with precise beam calibration and RFI rejection, setting sensitivity benchmarks for future FAST observations and informing target selection strategies.

Abstract

The Five-hundred-meter Aperture Spherical Telescope (FAST), the world's largest single-dish radio telescope, lists the search for extraterrestrial intelligence (SETI) as one of its key scientific objectives. In this work, we present a targeted SETI observation for 7 nearby active stars utilizing the FAST L-band multibeam receiver, employing a observational strategy that combines position switching with multibeam tracking to balance on-source integration time with the accuracy of the beam response. Using both pulsar and SETI backends, we perform a comprehensive search for narrowband drifting signals with Doppler drift rates within diversified drift rate ranges and channel-width periodic signal with periods between 0.12 and 100 s and duty cycles between 10% and 50%. No credible radio technosignatures were detected from any of the target systems. Based on this null result, we place constraints on the presence of transmitters at a 95% confidence level, ruling out narrowband transmitters with with EIRP above $3.98\times10^8 \,\mathrm{W}$ and periodic transmitter with EIRP above $1.80\times10^{10} \,\mathrm{W}$,respectively, within the observation band.

Dual-Backend Multibeam Position Switching Targeted SETI Observations toward Nearby Active Planet-Hosting Systems with FAST

TL;DR

This work applies FAST's high sensitivity to a targeted SETI survey of nearby planet-hosting systems, integrating multibeam position switching with dual backends to search for technosignatures in the 1.05–1.45 GHz band. The dual-backend approach enables complementary analyses of narrowband drifting signals and channel-width periodic signals, with rigorous RFI mitigation through multibeam calibration. No credible technosignatures were detected, allowing 95% confidence upper limits: narrowband transmitters with EIRP above W and periodic transmitters with EIRP above W within the observed band. The study demonstrates an efficient, robust SETI methodology with precise beam calibration and RFI rejection, setting sensitivity benchmarks for future FAST observations and informing target selection strategies.

Abstract

The Five-hundred-meter Aperture Spherical Telescope (FAST), the world's largest single-dish radio telescope, lists the search for extraterrestrial intelligence (SETI) as one of its key scientific objectives. In this work, we present a targeted SETI observation for 7 nearby active stars utilizing the FAST L-band multibeam receiver, employing a observational strategy that combines position switching with multibeam tracking to balance on-source integration time with the accuracy of the beam response. Using both pulsar and SETI backends, we perform a comprehensive search for narrowband drifting signals with Doppler drift rates within diversified drift rate ranges and channel-width periodic signal with periods between 0.12 and 100 s and duty cycles between 10% and 50%. No credible radio technosignatures were detected from any of the target systems. Based on this null result, we place constraints on the presence of transmitters at a 95% confidence level, ruling out narrowband transmitters with with EIRP above and periodic transmitter with EIRP above ,respectively, within the observation band.

Paper Structure

This paper contains 7 sections, 2 figures.

Table of Contents

  1. Introduction
  2. Observations
  3. Targets
  4. Planetary Habitability
  5. SETI/METI Search for the Targets
  6. Strategy
  7. Multibeam Position Switching Mode

Figures (2)

  • Figure 1: Observation targets in equatorial coordinates. The observable sky coverage of FAST is filled by yellow color.
  • Figure 2: Various HZ boundaries for stars with different effective temperatures. The five solid lines are the HZ boundaries determined by stellar flux HZ model of 2013ApJ...765..131K, and the green and brown shaded regions are the HZCL model of 2019ApJ...878...19S assuming limiting CO2 concentrations of 0.01 bar (dark green), 0.1 bar (lighter green), and 1 bar (lightest green). The brown contours denote regions around low-temperature stars where photochemical effects could allow CO concentrations to exceed short-term human safety thresholds ($>100$ ppm) at the moist greenhouse boundary, under an assumed surface flux of $3 \times 10^{11}$ molecules cm$^{-2}$ s$^{-1}$. The planetary parameters are from 2025ApJ...982L...1B for Barnard's star, 2024AA...690A.234L for Ross 128, 2024AA...688A.112V2010ApJ...723..954V for Gliese 581, 2012AA...545A...5L for Upsilon Andromedae A, 2010ApJ...722..937D2011ApJ...737L..18W2018AA...619A...1B for 55 Cancri A, 2022AJ....163..218H for Lalande 21185, and 2019arXiv190604644T2023AJ....166..260B for Wolf 359.