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Evolution of coronal helmets during the ascending phase of solar cycle 20

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Abstract

The principal polar-crown coronal helmet structures were selected from nearly three years (May, 1965–January, 1968) of K-coronameter observations made at Haleakala and Mauna Loa, Hawaii. Six isolated and long-lived helmet systems were found at latitudes of 45° and above. Their developments are compared with underlying chromospheric and photospheric activity and a simple phenomenological model is presented showing that a coronal system is formed over an active region. Thereafter the center of gravity of the system gradually drifts poleward with the trailing unipolar magnetic region (UMR), and it becomes a high latitude coronal helmet, arched over a polar crown filament.

By comparison of these coronal helmets with observations of the outer corona (to circa 4 R ⊙) made at solar eclipse, lunar sunset, and with balloon and rocket-borne externally occulted corona-graphs, it appears that ground-based K-coronameter measurements to a distance of 1.5–2.0 R ⊙ are sufficient to detect the coronal streamers.

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References

  • Altschuler, M. D. and Newkirk, G. A.: 1969, Solar Phys. 9, 131.

    Google Scholar 

  • Babcock, H. W. and Babcock, H. D.: 1955, Astrophys. J. 121, 349.

    Google Scholar 

  • Babcock, H. W.: 1961, Astrophys. J. 131, 572.

    Google Scholar 

  • Bohlin, J. D.: 1970a, Solar Phys. 12, 240.

    Google Scholar 

  • Bohlin, J. D.: 1970b, Solar Phys. 13, 153.

    Google Scholar 

  • Bohlin, J. D.: 1971, Solar Phys. 18, 450.

    Google Scholar 

  • Bohlin, J. D. and Simon, M.: 1969, Solar Phys. 9, 183.

    Google Scholar 

  • Billings, D. E.: 1966, A Guide to the Solar Corona, 1st Ed., Academic Press, New York.

    Google Scholar 

  • Bugoslavskaya, E. Y.: 1949, Publ. Sternberg Inst. 19.

  • Bumba, V. and Howard, R.: 1965a, Astrophys. J. 141, 1492.

    Google Scholar 

  • Bumba, V. and Howard, R.: 1965b, Astrophys. J. 141, 1502.

    Google Scholar 

  • Bumba, V., Howard, R., Martres, M. J., and Soru-Iscovici, I.: 1968, in K. O. Kiepenheuer (ed.), ‘Structure and Developments of Solar Active Regions’, IAU Symp. 35, 13.

  • Dodson, H. and Hedeman, R.: 1968, in K. O. Kiepenheuer (ed.), ‘Structure and Developments of Solar Active Regions’, IAU Symp. 35, 56.

  • Dollfus, A., Fort, B., and Morel, C.: Compt. Rend. Acad. Sci. Paris 266, 1537, 17 June 1968.

    Google Scholar 

  • Hansen, R. T., Hansen, S. F., and Garcia, C. J.: 1967, ‘The Solar Electron Corona of 12 November 1966’, HAO Astro-Geophys. Mem. No. 174.

  • Hansen, R. T., Garcia, C. J., Hansen, S. F., and Loomis, H. G.: 1969a, Solar Phys. 7, 417.

    Google Scholar 

  • Hansen, R. T., Hansen, S. F., and Loomis, H. G.: 1969b, Solar Phys. 10, 135.

    Google Scholar 

  • Hansen, R. T., Hansen, S. F., Garcia, C. J., and Trotter, D. E.: 1971, Solar Phys. 18, 271.

    Google Scholar 

  • Howard, R.: 1965, in R. Lüst (ed.), ‘Stellar and Solar Magnetic Fields’, IAU Symp. 22, 133.

  • Howard, R., Bumba, V., and Smith, S. F.: 1967, Atlas of Solar Magnetic Fields 1959–1966, Carnegie Institute of Washington, Publ. No. 626.

  • Hyder, C.: 1965, Astrophys. J. 141, 272.

    Google Scholar 

  • Koomen, M. J., Purcell, J. D., and Tousey, R.: 1966, Paper presented at the Special Meeting on Solar Astronomy of the American Astronomical Society, Boulder, Colorado, 3–5 October, 1966.

  • Kuperus, M.: 1965, Res. Astron. Obs. Utrecht 17, 1.

    Google Scholar 

  • LeBlanc, Y., Leroy, J. L., and Poulain, P.: 1970, Astron. Astrophys. 5, 391.

    Google Scholar 

  • Newkirk, G. A.: 1967, Ann. Rev. Astron. Astrophys. 5, 213.

    Google Scholar 

  • Newkirk, G. A. and Altschuler, M. D.: 1970, Solar Phys. 13, 131.

    Google Scholar 

  • Newkirk, G. A., Hansen, R. T., and Hansen, S. F.: 1967, Ann. IQSY 3, Paper 8.

  • Newkirk, G. A., Dupree, R. G., and Schmahl, E. J.: 1970, Solar Phys. 15, 15.

    Google Scholar 

  • Norton, R. H., Gunn, J. E., Livingston, W. C, Newkirk, G. A., and Zirin, H.: 1967, J. Geophys. Res. 72, 815.

    Google Scholar 

  • Osterbrock, D. E.: 1961, Astrophys. J. 134, 347.

    Google Scholar 

  • Pneuman, G. W. and Kopp, R. A.: 1970, Solar Phys. 13, 176.

    Google Scholar 

  • Pneuman, G. W. and Kopp, R. A.: 1971, Solar Phys. 18, 258.

    Google Scholar 

  • Purcell, J. D., Tousey, R. and Koomen, M. J.: 1968, Space Res. VIII, 450.

    Google Scholar 

  • Schatten, K. H.: 1968, Nature 220, 1211.

    Google Scholar 

  • Stenflo, J. O.: 1972, Solar Phys., in press.

  • Sturrock, P. A. and Smith, S. M.: 1968, Solar Phys. 5, 87.

    Google Scholar 

  • Sýkora, J.: 1969, Bull. Astron. Inst. Czech. 20, 70.

    Google Scholar 

  • Tousey, R., Sandlin, G. D., and Koomen, M. J.: 1968, in K. O. Kiepenheuer (ed.), ‘Structure and Developments of Solar Active Regions’, IAU Symp. 35, 385.

  • Van de Hulst, H. C.: 1953, in G. P. Kuiper (ed.), The Sun, Univ. of Chicago Press, Chicago.

    Google Scholar 

  • Waldmeier, M.: 1967, Z. Astrophys. 67, 463.

    Google Scholar 

  • Wlérick, G. and Axtell, J.: 1957, Astrophys. J. 126, 253.

    Google Scholar 

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Authors and Affiliations

  1. High Altitude Observatory, National Center for Atmospheric Research, Boulder, Colo., U.S.A.

    Shirley F. Hansen, Richard T. Hansen & Charles J. Garcia

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  1. Shirley F. Hansen
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  2. Richard T. Hansen
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  3. Charles J. Garcia
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The National Center for Atmospheric Research is sponsored by the National Science Foundation.

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Hansen, S.F., Hansen, R.T. & Garcia, C.J. Evolution of coronal helmets during the ascending phase of solar cycle 20. Sol Phys 26, 202–224 (1972). https://doi.org/10.1007/BF00155120

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  • DOI: https://doi.org/10.1007/BF00155120

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