Hostname: page-component-7bb8b95d7b-cx56b Total loading time: 0 Render date: 2024-09-17T21:55:50.407Z Has data issue: false hasContentIssue false
  • English
  • Français

On Sunspot and Facular Contrast Variations Near 2 μm and 4 μm

Published online by Cambridge University Press:  03 August 2017

V. A. Kotov  and
S. Koutchmy
V. A. Kotov
Affiliation:
CSSA, Stanford University, Stanford, CA 94305, U.S.A. Crimean Astrophysical Observatory, Nauchny, Crimea 334413, USSR
S. Koutchmy
Affiliation:
Institut d'Astrophysique, CNRS, 98 bis, Boulevard Arago, F-75014 Paris, France

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Observations of the Sun at 2.2 and 3.75 μm have been made at the Pic-du-Midi and Crimean observatories. High resolution (~ 1″) records of the sunspot and facular contrasts at various heliocentric distances as well as those at the extreme solar limb are presented. We find substantial variations in the sunspot-core relative intensity caused by magnetic activity of the spot. The extreme-limb contrasts of faculae at 3.75 μm are strong thus support flux-tube models which result in an enhancement of the extreme-limb facular brightness.

Keywords

flux tubesinfrared: starsSun: faculae, plagessunspots
Type
Part 3: Infrared Perspectives on Atmospheric Dynamics
Information
Symposium - International Astronomical Union , Volume 154: Infrared Solar Physics , 1994 , pp. 265 - 270
Copyright
Copyright © Kluwer 1994 

References

Albregtsen, F., Joras, P.B., and Maltby, P.: 1984, Solar Phys. 90, 17.Google Scholar
Allen, C.W.: 1976, Astrophysical Quantities, Athlone Press, London.Google Scholar
Ekmann, G., and Maltby, P.: 1974, Solar Phys. 35, 317.CrossRefGoogle Scholar
Foukal, P., Harvey, K., and Hill, F.: 1991, Astrophys. J. 383, L89.CrossRefGoogle Scholar
Koutchmy, S., Koutchmy, O., and Kotov, V.: 1977, Astron. Astrophys. 59, 189.Google Scholar
Koutchmy, S., and Stellmacher, G.: 1978, Astron. Astrophys. 67, 93.Google Scholar
Lindsey, C., and Heasley, J.N.: 1981, Astrophys. J. 247, 348.CrossRefGoogle Scholar
Makita, M., and Morimoto, M.: 1960, Pub. Astron. Soc. Japan 12, 63.Google Scholar
Maltby, P.: 1972, Solar Phys. 26, 76.CrossRefGoogle Scholar
Mattig, W.: 1969, Solar Phys. 6, 413.CrossRefGoogle Scholar
Wittmann, A., and Schröter, E.H.: 1969, Solar Phys. 10, 357.CrossRefGoogle Scholar