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On the apparent velocity of integrated sunlight. 2: 1983-1992 and comparisons with magnetogramsWe report additional results in our program to monitor the wavelength stability of lines in the 2.3 micrometer spectrum of integrated sunlight. We use the McMath Fourier transform spectrometer (FTS) of the National Solar Observatory to monitor 16 delta V = 2 lines of (12)C(16)O, as well as five atomic lines. Wavenumber calibration is achieved using a low-pressure N2O absorption cell and checked against terrestrial atmospheric lines. Imperfect optical integration of the solar disk remains the principal source of error, but this error has been reduced by improved FTS/telescope collimation and observing procedures. The present results include data from an additional 13 quarterly observing runs since 1985. We continue to find that the apparent velocity of integrated sunlight is variable, in the sense of having a greater reshift at solar maximum. This is supported by the temporal dependence of the integrated light velocity, and by the presence of a correlation between velocity and the disk-averaged magnetic flux derived from Kitt Peak magnetograms. The indicated peak-to-peak apparent velocity amplitude over a solar cycle is approximately the same as the velocity amplitude of the Sun's motion about the solar system barycenter. This represents about half the amplitude which we inferred in Paper I (Deming et al. 1987), but the present result has a much greater statistical significance. Our results have implications for those investigations which search for the Doppler signatures of planetary-mass companions to solar-type stars. We contrast our results to the recent finding by McMillan et al. 1993 that solar absorption lines in the violet spectral region are wavelength-stable over the solar cycle.
Document ID
19950038793
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Deming, Drake
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Plymate, Claude
(National Solar Observatory, Tucson, AZ United States)
Date Acquired
August 16, 2013
Publication Date
May 1, 1994
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 426
Issue: 1
ISSN: 0004-637X
Subject Category
Astronomy
Accession Number
95A70392
Funding Number(s)
PROJECT: RTOP 196-41-54
Distribution Limits
Public
Copyright
Other

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