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Five years of Project META - An all-sky narrow-band radio search for extraterrestrial signalsWe have conducted a five-year search of the northern sky (delta between 30 and 60 deg) for narrow-band radio signals near the 1420 MHz line of neutral hydrogen, and its second harmonic, using an 8.4 x 10 exp 6 channel Fourier spectrometer of 0.05 Hz resolution and 400 kHz instantaneous bandwidth. The observing frequency was corrected both for motions with respect to three astronomical inertial frames, and for the effect of Earth's rotation, which provides a characteristic changing Doppler signature for narrow-band signals of extraterrestrial origin. Among the 6 x 10 exp 13 spectral channels searched, we have found 37 candidate events exceeding the average detection threshold of 1.7 x 10 exp -23 W/sq m, none of which was detected upon reobservation. The strongest of these appear to be dominated by rare processor errors. However, the strongest signals that survive culling for terrestrial interference lie in or near the Galactic plane. We describe the search and candidate events, and set limits on the prevalence of supercivilizations transmitting Doppler-precompensated beacons at H I or its second harmonic. We conclude with recommendations for future searches, based upon these findings, and a description of our next-generation search system.
Document ID
19930072472
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Horowitz, Paul
(Harvard Univ. Cambridge, MA, United States)
Sagan, Carl
(Cornell Univ. Ithaca, NY; Planetary Society, Pasadena, CA, United States)
Date Acquired
August 16, 2013
Publication Date
September 20, 1993
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 415
Issue: 1
ISSN: 0004-637X
Subject Category
Space Sciences (General)
Accession Number
93A56469
Distribution Limits
Public
Copyright
Other

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