A Green Bank Telescope Search for Narrowband Technosignatures between 1.1 and 1.9 GHz During 12 Kepler Planetary Transits

Sofia Z. Sheikh; Shubham Kanodia; Emily Lubar; Graduate SETI Course at Penn State; William P. Bowman; Caleb I. Cañas; Christian Gilbertson; Mariah G. MacDonald; Jason Wright; The Breakthrough Listen Initiative; David MacMahon; Steve Croft; Danny Price; Andrew Siemion; Jamie Drew; S. Pete Worden; Elizabeth Trenholm

doi:10.3847/1538-3881/aca907

The Astronomical Journal (Jan 2023)

A Green Bank Telescope Search for Narrowband Technosignatures between 1.1 and 1.9 GHz During 12 Kepler Planetary Transits

Sofia Z. Sheikh,
Shubham Kanodia,
Emily Lubar,
Graduate SETI Course at Penn State,
William P. Bowman,
Caleb I. Cañas,
Christian Gilbertson,
Mariah G. MacDonald,
Jason Wright,
The Breakthrough Listen Initiative,
David MacMahon,
Steve Croft,
Danny Price,
Andrew Siemion,
Jamie Drew,
S. Pete Worden,
Elizabeth Trenholm

Affiliations

Sofia Z. Sheikh: ORCiD; SETI Institute , 339 Bernardo Avenue, Suite 200, Mountain View, CA 94043, USA ; [email protected]; Berkeley SETI Research Center, University of California , Berkeley, CA 94720, USA; Penn State Extraterrestrial Intelligence Center, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA
Shubham Kanodia: ORCiD; Penn State Extraterrestrial Intelligence Center, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA; Earth and Planets Laboratory, Carnegie Institution for Science , 5241 Broad Branch Road, NW, Washington, DC 20015, USA; Department of Astronomy & Astrophysics, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA; Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA
Emily Lubar: ORCiD; Department of Astronomy, University of Texas at Austin , Austin, TX, USA
Graduate SETI Course at Penn State
William P. Bowman: ORCiD; Department of Astronomy & Astrophysics, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802, USA
Caleb I. Cañas: ORCiD; Department of Astronomy & Astrophysics, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA; Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA
Christian Gilbertson: ORCiD; Department of Astronomy & Astrophysics, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA; Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA
Mariah G. MacDonald: ORCiD; Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA; Department of Physics, The College of New Jersey , 2000 Pennington Road, Ewing, NJ 08628, USA
Jason Wright: ORCiD; Penn State Extraterrestrial Intelligence Center, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA; Department of Astronomy & Astrophysics, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA; Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University , University Park, PA 16802, USA
The Breakthrough Listen Initiative
David MacMahon: Berkeley SETI Research Center, University of California , Berkeley, CA 94720, USA; Radio Astronomy Lab, University of California , Berkeley, CA 94720, USA
Steve Croft: ORCiD; SETI Institute , 339 Bernardo Avenue, Suite 200, Mountain View, CA 94043, USA ; [email protected]; Berkeley SETI Research Center, University of California , Berkeley, CA 94720, USA; Radio Astronomy Lab, University of California , Berkeley, CA 94720, USA
Danny Price: ORCiD; Berkeley SETI Research Center, University of California , Berkeley, CA 94720, USA; International Centre for Radio Astronomy Research , 1 Turner Avenue, Bentley WA 6102, Australia
Andrew Siemion: ORCiD; SETI Institute , 339 Bernardo Avenue, Suite 200, Mountain View, CA 94043, USA ; [email protected]; Berkeley SETI Research Center, University of California , Berkeley, CA 94720, USA; Department of Physics and Astronomy, University of Manchester , UK; Institute of Space Sciences and Astronomy, University of Malta , Malta
Jamie Drew: Breakthrough Initiatives, NASA Research Park , Moffett Field, CA 94035, USA
S. Pete Worden: Breakthrough Initiatives, NASA Research Park , Moffett Field, CA 94035, USA
Elizabeth Trenholm: ORCiD; University of Greenwich , School of Computing and Mathematical Sciences, Park Row, SE10 9LS, London, UK

DOI: https://doi.org/10.3847/1538-3881/aca907
Journal volume & issue: Vol. 165, no. 2
p. 61

Abstract

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Agrowing 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 to perform the first technosignature search presynchronized with exoplanet transits, covering 12 Kepler systems. We used the Breakthrough Listen turboSETI pipeline to flag narrowband hits (∼3 Hz) using a maximum drift rate of ±614.4 Hz s ^−1 and a signal-to-noise threshold of 5—the pipeline returned ∼3.4 × 10 ^5 apparently-localized features. Visual inspection by a team of citizen scientists ruled out 99.6% of them. Further analysis found two signals of interest that warrant follow up, but no technosignatures. If the signals of interest are not redetected in future work, it will imply that the 12 targets in the search are not producing transit-aligned signals from 1.1 to 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.

Published in The Astronomical Journal

ISSN: 0004-6256 (Print); 1538-3881 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy
Website: https://iopscience.iop.org/journal/1538-3881

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