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Observations of the Polar Magnetic Fields

Published online by Cambridge University Press:  14 August 2015

Jan Olof Stenflo*
Affiliation:
Astronomical Observatory, Lund, Sweden

Abstract

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Results from observations of the polar magnetic fields made in 1968 with the Mount Wilson magnetograph are reported. The field was of south polarity near the heliographic north pole and of north polarity near the south pole. The inversion line of the field was at latitude +70° in the north hemisphere and −55° in the south, which coincides with the position of the polar prominence zones at that time. Observations made simultaneously at the Crimean Astrophysical Observatory are in good agreement with the Mt. Wilson data and confirm the latitude variation of the field.

A few hundred of Hale's plates from 1914, which he had used to determine the Sun's general magnetic field, have been remeasured. The plates were automatically scanned with a digitized microphotometer, and the treatment of the data was made with a computer. While the visual measurements by Van Maanen had given a strong general field similar to that of a dipole, the computer reductions did not reveal any significant field (stronger than 5 G) at any latitude.

Type
Part VII: The Polar Fields of the Sun and the Magnetic Activity Cycle
Copyright
Copyright © Reidel 1971 

References

Babcock, H. D.: 1959, Astrophys. J. 130, 364.CrossRefGoogle Scholar
Babcock, H. W.: 1961, Astrophys. J. 133, 572.CrossRefGoogle Scholar
Babcock, H. W. and Babcock, H. D.: 1955, Astrophys. J. 121, 349.CrossRefGoogle Scholar
Bumba, V., Kleczek, J., Olmr, J., and Ruzickova-Topolova, B.: 1969, Bull. Astron. Inst. Czech. 20, 67.Google Scholar
Hale, G. E.: 1912, Terrest. Magn. Atmospheric Electr. 17, 173.CrossRefGoogle Scholar
Hale, G. E.: 1913, Astrophys. J. 38, 27.CrossRefGoogle Scholar
Hale, G. E., Seares, F. H., Van Maanen, A., and Ellerman, F.: 1918, Astrophys. J. 47, 206.CrossRefGoogle Scholar
Harvey, J. and Livingston, W.: 1969, Solar Phys. 10, 283.CrossRefGoogle Scholar
Kotov, V. A. and Stenflo, J. O.: 1970, Solar Phys. 15, 265.CrossRefGoogle Scholar
Leighton, R. B.: 1969, Astrophys. J. 156, 1.CrossRefGoogle Scholar
Lundmark, K.: 1927, Uppsala Astron. Obs. Medd. No. 30.Google Scholar
Rosseland, S.: 1925, Astrophys. J. 62, 387.CrossRefGoogle Scholar
Seares, F. H., Van Maanen, A., and Ellerman, F.: 1918, Proc. Nat. Acad. Sci. 4, 4.CrossRefGoogle Scholar
Seares, F. H., Van Maanen, A., and Ellerman, F.: 1919, Proc. Nat. Acad. Sci. 5, 242.CrossRefGoogle Scholar
Steenbeck, M.: 1966a, Wissenschaft und Menschheit 2, 315, Urania-Verlag Leipzig/Jena/Berlin.Google Scholar
Steenbeck, M. and Krause, F.: 1966b, Z. Naturforsch. 21a, 1285.CrossRefGoogle Scholar
Steenbeck, M. and Krause, F.: 1967, Gustav-Hertz-Festschrift , Akademie-Verlag, Berlin.Google Scholar
Steenbeck, M. and Krause, F.: 1969, Astron. Nachr. 291, 49.CrossRefGoogle Scholar
Stenflo, J. O.: 1970a, Solar Phys. 13, 42.CrossRefGoogle Scholar
Stenflo, J. O.: 1970b, Solar Phys. 14, 263.CrossRefGoogle Scholar
Waldmeier, M.: 1960, Z. Astrophys. 49, 176.Google Scholar
Waldmeier, M.: 1969, Astron. Mitt. Zürich Nr. 288.Google Scholar