The Breakthrough Listen Search for Intelligent Life: A 3.95–8.00 GHz Search for Radio Technosignatures in the Restricted Earth Transit Zone

Journal Article · Wed Jul 01 04:00:00 EDT 2020 · The Astronomical Journal (Online)

DOI:https://doi.org/10.3847/1538-3881/AB9361· OSTI ID:23013264

Sheikh, Sofia Z. ^[1]; Siemion, Andrew; Enriquez, J. Emilio; Price, Danny C.; Isaacson, Howard; Lebofsky, Matt; Gajjar, Vishal; Kalas, Paul ^[2]

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1. Department of Astronomy & Astrophysics, Center for Exoplanets and Habitable Worlds, and Penn State Extraterrestrial Intelligence Center, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States)
2. Department of Astronomy, University of California, Berkeley, 501 Campbell Hall 3411, Berkeley, CA, 94720 (United States)

We report on a search for artificial narrowband signals of 20 stars within the restricted Earth Transit Zone (rETZ) as a part of the ten-year Breakthrough Listen (BL) search for extraterrestrial intelligence (ETI). The rETZ is the region of the sky from which an observer would see Earth transit the Sun with an impact parameter of less than 0.5. This region of the sky is geometrically unique, providing a potential way for an ETI to discover the solar system. The targets were nearby (7–143 pc) and the search covered an electromagnetic frequency range of 3.95–8.00 GHz. We used the Robert C. Byrd Green Bank Telescope to perform these observations with the standard BL data recorder. We searched these data for artificial narrowband (∼Hz) signals with Doppler drift rates of ±20 Hz s{sup −1}. We find no evidence for radio technosignatures from ETI in our observations. The observing campaign would have allowed for detections of emissions that were 10{sup −3} to 0.88 times as powerful as the signaling capability of the Arecibo radar transmitter. We conclude that at least 0.6% of the systems in the rETZ within 150 pc do not possess the type of transmitters searched in this survey. To our knowledge, this is the first targeted search for ETI of the rETZ. All data used in this paper are publicly available via the BL Public Data Archive (http://seti.berkeley.edu/bldr2).

• OSTI ID: 23013264
• Journal Information: The Astronomical Journal (Online), Journal Name: The Astronomical Journal (Online) Journal Issue: 1 Vol. 160; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DETECTION
EARTH PLANET
EMISSION
IMPACT PARAMETER
SOLAR SYSTEM
SUN
TELESCOPES