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Streaming Magnetic Features near Sunspots

Published online by Cambridge University Press:  14 August 2015

Dale Vrabec
Dale Vrabec*
Affiliation:
San Fernando Observatory and Space Physics Laboratory, The Aerospace Corporation, Los Angeles, Calif., U.S.A.

Abstract

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Observations prompted by Sheeley's discovery of outflowing CN bright points from sunspots have established that there occur small moving magnetic features (MMF's) near sunspots. These MMF's exhibit a highly ordered pattern of movement directly related to the associated sunspot. The observations are consistent with the concept of magnetic flux outflow (MFO), a process whereby net magnetic flux of the same polarity as the sunspot is transferred from a decaying sunspot to the surrounding magnetic network. Small magnetic flux concentrations are apparently convected outward by a velocity cell centered on the sunspot. Doppler spectroheliograms have provided evidence for such systematic outward velocities extending as far as 10000 to 20000 km beyond the outer edge of the penumbra of some sunspots, which is comparable to the extent of MFO. While MFO is best observed by means of time-lapse movies of the magnetic fields, it is also manifested morphologically on individual magnetograms by features that resemble moats (or bays) and wreaths around only those sunspots where MFO is present. Two examples of magnetic features streaming toward and into rapidly forming sunspots are described, providing evidence for the occurrence of magnetic flux inflow (MFI) associated with the growth phase of sunspot development. It is, therefore, likely that MFI and MFO are basic aspects of the evolutionary development of sunspots. Observational and instrumental aspects relevant to the investigation of MMF's are described in the Appendix.

Type
Part VI: Evolution of Chromospheric Fine Structures
Information
Symposium - International Astronomical Union , Volume 56: Chromospheric Fine Structure , 1974 , pp. 201 - 231
Copyright
Copyright © Reidel 1974 

References

Allen, R., Edberg, S., LaBonte, B., and Sheeley, N. R.: 1973, Bull. Amer. Astron. Soc. 5, 268.Google Scholar
Beckers, J. M.: 1971, in Howard, R. (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 3.Google Scholar
Beckers, J. M.: 1973, Bull. Amer. Astron. Soc. 5, 269.Google Scholar
Beckers, J. M. and Schröter, E. H.: 1968, Solar Phys. 4, 142.CrossRefGoogle Scholar
Bray, R. J. and Loughhead, R. E.: 1964, Sunspots, Chapman and Hall, Ltd., London, p. 186.Google Scholar
Bruzek, A.: 1967, Solar Phys. 2, 451.Google Scholar
Bruzek, A.: 1969, Solar Phys. 8, 29.CrossRefGoogle Scholar
Bumba, V.: 1965, in Lüst, R. (ed.), ‘Stellar and Solar Magnetic Fields’, IAU Symp. 22, 305.Google Scholar
Bumba, V. and Suda, J.: 1973, in Coffey, H. E. (ed.), Report UAG-28, Part 1, ‘Collected Data Reports on August 1972 Solar-Terrestrial Events’, World Data Center A for Solar-Terrestrial Physics, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Environmental Data Service, Asheville, North Carolina, U.S.A., p. 155.Google Scholar
Chapman, G. A.: 1970, Solar Phys. 13, 78.CrossRefGoogle Scholar
Chapman, G. A.: 1972, Solar Phys. 26, 299.Google Scholar
Chapman, G. A.: 1973, in Coffey, H. E. (ed.), Report UAG-28, Part 1, ‘Collected Data Reports on August 1972 Solar-Terrestrial Events’, World Data Center A for Solar-Terrestrial Physics, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Environmental Data Service, Asheville, North Carolina, U.S.A., p. 85.Google Scholar
Coffey, H. E.: 1973, ibid. Google Scholar
Dunn, R. B. and Spence, G. E.: 1973, Bull. Amer. Astron. Soc. 5, 271.Google Scholar
Evans, J. W.: 1966, in Proceedings of the Meeting on Solar Magnetic Fields and High Resolution Spectroscopy, Rome, 14–16 September , p. 123.Google Scholar
Frazier, E. N.: 1972, Solar Phys. 26, 130.CrossRefGoogle Scholar
Frazier, E. N. and Stenflo, J. O.: 1972, Solar Phys. 27, 330.Google Scholar
Harvey, J.: 1971, Publ. Astron. Soc. Pacific 83, 539.Google Scholar
Harvey, J., Livingston, W., and Slaughter, G.: 1972, in ‘Line Formation in the Presence of Magnetic Fields’, High Altitude Observatory, National Center for Atmospheric Research, p. 227.Google Scholar
Harvey, K.: 1973, private communication.Google Scholar
Harvey, K. and Harvey, J.: 1972, Bull. Amer. Astron. Soc. 4, 384.Google Scholar
Harvey, K. and Harvey, J.: 1973, Solar Phys. 28, 61.CrossRefGoogle Scholar
Howard, R. and Stenflo, J. O.: 1972, Solar Phys. 22, 402.Google Scholar
Janssens, T. J.: 1970, Solar Phys. 11, 222.Google Scholar
Janssens, T. J. and Baker, N. K.: 1971, in Howard, R. (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 44.Google Scholar
Leighton, R. B.: 1959, Astrophys. J. 130, 366.Google Scholar
Leighton, R. B., Noyes, R. W., and Simon, G. W.: 1962, Astrophys. J. 135, 474.CrossRefGoogle Scholar
Livingston, W. C.: 1972, Sky Telesc. 43, 344.Google Scholar
Livingston, W. C.: 1973, private communication.Google Scholar
Livingston, W. C. and Harvey, J. W.: 1969, Solar Phys. 10, 294.Google Scholar
Livingston, W. C. and Harvey, J. W.: 1971, in Howard, R. (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 51.Google Scholar
McIntosh, P. S.: 1967, oral communication presented at IAU Symp. 35 on the ‘Structure and Development of Solar Active Regions’, Budapest, Hungary, 4–8 September.Google Scholar
McIntosh, P. S.: 1969, in Stickland, A. C. (ed.), Annals of the IQSY, Vol. 3, ‘The Proton Flare Project, (The July 1966 Event)’, The MIT Press, Cambridge, Massachusetts, p. 40.Google Scholar
McIntosh, P. S.: 1972, in Coffey, H. E. and Lincoln, J. V. (eds.), Report UAG-24, Part II, ‘Data on Solar-Geophysical Activity Associated with the Major Ground Level Cosmic Ray Events of 24 January and 1 September 1971’, World Data Center A for Solar-Terrestrial Physics, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Environmental Data Service, Asheville, North Carolina, U.S.A., p. 303.Google Scholar
McIntosh, P. S.: 1973, private communication.Google Scholar
Michard, R., Mouradian, Z., and Semel, M.: 1961, Ann. Astrophys. 24, 54.Google Scholar
Pfister, H. J.: 1973, in Coffey, H. E. (ed.), Report UAG-28, Part 1, ‘Collected Data Reports on August 1972 Solar-Terrestrial Events’, World Data Center A for Solar-Terrestrial Physics, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Environmental Data Service, Asheville, North Carolina, U.S.A., p. 35.Google Scholar
Ramsay, J. V., Kobler, H., and Mugridge, E. G. V.: 1970, Solar Phys. 12, 492.Google Scholar
Ramsay, J. V., Giovanelli, R. G., and Gillett, H. R.: 1971, in Howard, R. (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 24.Google Scholar
Rogers, E. H.: 1970, Solar Phys. 13, 57.Google Scholar
Schatz, D. L.: 1971, in Howard, R. (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 243.Google Scholar
Schoolman, S. A.: 1972, Bull. Amer. Astron. Soc. 4, 390.Google Scholar
Schoolman, S. A.: 1973, Solar Phys. 32, 379.Google Scholar
Sheeley, N. R.: 1967, Solar Phys. 1, 171.Google Scholar
Sheeley, N. R.: 1969, Solar Phys. 9, 347.Google Scholar
Sheeley, N. R.: 1971, in Howard, R. (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 310.Google Scholar
Sheeley, N. R.: 1972, Solar Phys. 25, 98.Google Scholar
Sheeley, N. R.: 1973, private communication.Google Scholar
Sheeley, N. R. and Bhatnagar, A.: 1971a, Solar Phys. 18, 195.CrossRefGoogle Scholar
Sheeley, N. R. and Bhatnagar, A.: 1971b, Solar Phys. 19, 338.Google Scholar
Simon, G. W.: 1966, in Kiepenheuer, K. O. (ed.), The Fine Structure of the Solar Atmosphere , F. Steiner Verlag, Wiesbaden, West Germany, p. 47.Google Scholar
Simon, G. W. and Leighton, R. B.: 1964, Astrophys. J. 140, 1120.Google Scholar
Simon, G. W. and Zirker, J. B.: 1973, Bull. Amer. Astron. Soc. 5, 280.Google Scholar
Smithson, R. C.: 1972, Bull Amer. Astron. Soc. 4, 392.Google Scholar
Smithson, R. C.: 1973a, Bull. Amer. Astron. Soc. 5, 280.Google Scholar
Smithson, R. C.: 1973b, Solar Phys. 29, 365.Google Scholar
Smithson, R. C. and Leighton, R. B.: 1971, in Howard, R. (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 76.Google Scholar
Tandberg-Hanssen, : 1967, Solar Activity, Blaisdell Publishing Co., Waltham, Massachusetts, p. 181.Google Scholar
Title, A.: 1970, ‘Fabry-Pérot Interferometers as Narrow-Band Optical Filters, Part 1, Theoretical Considerations’, TR-18, Harvard College Observatory, p. 75.Google Scholar
Title, A. M. and Andelin, J. P.: 1971, in Howard, R. (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 298.Google Scholar
Vrabec, D.: 1971, in Howard, R. (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 329.Google Scholar
Vrabec, D. and Janssens, T. J.: 1972, Solar Phys. 25, 2.Google Scholar
Weart, S. R.: 1970, Astrophys. J. 162, 987.Google Scholar
Weart, S. R.: 1972, Astrophys. J. 177, 271.Google Scholar
Weart, S. R. and Zirin, H.: 1969, Publ. Astron. Soc. Pacific 81, 270.Google Scholar
Zirin, H.: 1966, The Solar Atmosphere , Blaisdell Publishing Co., Waltham, Massachusetts, p. 33.Google Scholar
Zirin, H.: 1970, Solar Phys. 14, 328.Google Scholar
Zirin, H. and Tanaka, K.: 1973, Solar Phys. 32, 173.Google Scholar