A Green Bank Telescope search for narrowband technosignatures between 1.1-1.9 GHz during 12 Kepler planetary transits

Abstract

A growing avenue for determining the prevalence of life beyond Earth is to search for "technosignatures" from extraterrestrial intelligences/agents. Technosignatures require significant energy to be visible across interstellar space and thus intentional signals might be concentrated in frequency, in time, or in space, to be found in mutually obvious places. Therefore, it could be advantageous to search for technosignatures in parts of parameter space that are mutually-derivable to an observer on Earth and a distant transmitter. In this work, we used the L-band (1.1-1.9 GHz) receiver on the Robert C. Byrd Green Bank Telescope (GBT) to perform the first technosignature search pre-synchronized with exoplanet transits, covering 12 Kepler systems. We used the Breakthrough Listen turboSETI pipeline to flag narrowband hits ($\sim$3 Hz) using a maximum drift rate of $\pm$614.4 Hz/s and a signal-to-noise threshold of 5 - the pipeline returned $\sim 3.4\times 10^5$ apparently-localized features. Visual inspection by a team of citizen scientists ruled out 99.6% of them. Further analysis found 2 signals-of-interest that warrant follow-up, but no technosignatures. If the signals-of-interest are not re-detected in future work, it will imply that the 12 targets in the search are not producing transit-aligned signals from 1.1-1.9 GHz with transmitter powers $>$60 times that of the former Arecibo radar. This search debuts a range of innovative technosignature techniques: citizen science vetting of potential signals-of-interest, a sensitivity-aware search out to extremely high drift rates, a more flexible method of analyzing on-off cadences, and an extremely low signal-to-noise threshold.

18 pages, 11 figures

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Cited by in corpus (6)

• The Breakthrough Listen Search for Intelligent Life: Technosignature Search of 97 Nearby Galaxies
• A Radio Technosignature Search of TRAPPIST-1 with the Allen Telescope Array
• Earth Detecting Earth: At what distance could Earth's constellation of technosignatures be detected with present-day technology?
• A solution to continuous RFI in narrowband radio SETI with FAST: The MultiBeam Point-source Scanning strategy
• Detecting Extraterrestrial Civilizations That Employ an Earth-level Deep Space Network
• Breakthrough Listen: A Technosignature Search Around 27 Eclipsing Exoplanets Selected from the Transiting Exoplanet Survey Satellite Catalogue