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Proceedings Paper

Targeted and all-sky search for nanosecond optical pulses at Harvard-Smithsonian
Author(s): Paul Horowitz; Charles M. Coldwell; Andrew B. Howard; David W. Latham; Robert Stefanik; Jonathan Wolff; Joe M. Zajac
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Paper Abstract

We have built a system to detect nanosecond pulsed optical signals from a target list of some 10,000 sun-like stars, and have made some 20,000 observations during its two years of operation. A beamsplitter feeds a pair of hybrid avalanche photodetectors at the focal plane of the 1.5m Cassegrain at the Harvard/Smithsonian Oak Ridge Observatory (Agassiz Station), with a coincidence triggering measurement of pulse width and intensity at sub-nanosecond resolution. A flexible web-enabled database, combined with mercifully low background coincidence rates (approximately 1 event per night), makes it easy to sort through far-flung data in search of repeated events from any candidate star. An identical system will soon begin observations, synchronized with ours, at the 0.9m Cassegrain at Princeton University. These will permit unambiguous identification of even a solitary pulse. We are planning an all-sky search for optical pulses, using a dedicated 1.8m f/2.4 spherical glass light bucket and an array of pixelated photomultipliers deployed in a pair of matched focal planes. The sky pixels, 1.5 arcmin square, tessellate a 1.6 by 0.2 degree patch of sky in transit mode, covering the Northern sky in approximately 150 clear nights. Fast custom IC electronics will monitor corresponding pixels for coincident optical pulses of nanosecond timescale, triggering storage of a digitized waveform of the light flash.

Paper Details

Date Published: 3 August 2001
PDF: 9 pages
Proc. SPIE 4273, The Search for Extraterrestrial Intelligence (SETI) in the Optical Spectrum III, (3 August 2001); doi: 10.1117/12.435364
Show Author Affiliations
Paul Horowitz, Harvard Univ. (United States)
Charles M. Coldwell, Harvard Univ. (United States)
Andrew B. Howard, Harvard Univ. (United States)
David W. Latham, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Robert Stefanik, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Jonathan Wolff, SpaceDev Inc. (United States)
Joe M. Zajac, Harvard-Smithsonian Ctr. for Astrophysics (United States)

Published in SPIE Proceedings Vol. 4273:
The Search for Extraterrestrial Intelligence (SETI) in the Optical Spectrum III
Stuart A. Kingsley; Ragbir Bhathal, Editor(s)

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