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The IR Contrast of Magnetic Elements Obtained from High Spatial Resolution Observations at 1.6 μm

Published online by Cambridge University Press:  03 August 2017

Tron A. Darvann  and
Serge Koutchmy
Tron A. Darvann
Affiliation:
Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo 3, Norway National Solar Observatory,* Sunspot, NM 88349, U.S.A.
Serge Koutchmy
Affiliation:
Institut d'Astrophysique, CNRS, 98 Bis, Blvd. Arago, F-75014 Paris, France National Solar Observatory,* Sunspot, NM 88349, U.S.A.

Abstract

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We report on new improved infrared (IR) imaging observations (1.6 μm) carried out with the National Solar Observatory's Vacuum Tower Telescope at Sacramento Peak, New Mexico (NSO/SP). Examples of high spatial resolution (up to 0.4″ images are shown, and results of comparisons between infrared and continuum at 526 nm and between infrared and the locations of enhanced magnetic field (“fluxtube regions” as defined by Mg I b1 line imaging) are given and discussed. Our results indicate that, close to disk center, magnetic elements have a positive contrast at the opacity minimum. This is contrary to the findings of several other authors (e.g., Worden 1975, Foukal et al. 1990). We emphasize the necessity of multi-color, high spatial and temporal resolution observations. The potential of present “almost-on-a-routine-basis” IR observations utilizing a fast video acquisition system developed at NSO/SP is pointed out.

Keywords

infrared: starsSun: faculae, plagesSun: magnetic fields
Type
Part 5: Magnetic Fields and Infrared Magnetometry
Information
Symposium - International Astronomical Union , Volume 154: Infrared Solar Physics , 1994 , pp. 483 - 488
Copyright
Copyright © Kluwer 1994 

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