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Proceedings Paper

An Orbiting Infrared Interferometer To Search For Nonsolar Planets
Author(s): Robert H. MacPhie; Ronald N. Bracewell
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Paper Abstract

If the solar system were observed from afar, the sun's visible light would be about 109 times stronger 4 than the light reflected from Jupiter. But in the far infrared (40 μm) the solar radiation is only 2 x 10 times the jovian. This paper proposes an orbiting infrared interferometer with its fringe null centered on a nearby star at a distance of say 10 parsecs. A large planet ("Jupiter") would have an angular separation from the star of about 0.5 arcsec. To have a fringe crest on the planet, a fringe period of 1.0 arcsec is needed and at 40 μm the required baseline is 8 m. Spinning the interferometer about the line of sight to the star results, even with pointing errors, in a relatively slowly varying but strongly suppressed stellar output and a more rapidly varying fringe-like planetary signal rich in higher harmonics. For pointing errors up to .050 arcsec the planet's fourth harmonic greatly exceeds that from the star, thereby relaxing interferometer pointing tolerances. Indeed, it appears that the limiting factor is zodiacal infrared background radiation and not the intense localized stellar flux which can effectively be eliminated by the fringe null of the spinning infrared interferometer.

Paper Details

Date Published: 3 May 1979
PDF: 8 pages
Proc. SPIE 0172, Instrumentation in Astronomy III, (3 May 1979); doi: 10.1117/12.957091
Show Author Affiliations
Robert H. MacPhie, University of Waterloo, (Canada)
Ronald N. Bracewell, Stanford University (United States)

Published in SPIE Proceedings Vol. 0172:
Instrumentation in Astronomy III
David L. Crawford, Editor(s)

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