Hostname: page-component-848d4c4894-nmvwc Total loading time: 0 Render date: 2024-06-22T06:45:32.819Z Has data issue: false hasContentIssue false
  • English
  • Français

Solar and stellar magnetic flux tubes

Published online by Cambridge University Press:  25 May 2016

Sami K. Solanki
Sami K. Solanki*
Affiliation:
Institute of Astronomy ETH-Zentrum, CH-8092 Zürich, Switzerland

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.

The magnetic field of the Sun is mainly concentrated into intense magnetic flux tubes having field strengths of the order of 1 kG. In this paper an overview is given of the thermal and magnetic properties of these flux tubes, which are known to exhibit a large range in size, from the smallest magnetic elements to sunspots. Differences and similarities between the largest and smallest features are stressed. Some thoughts are also presented on how the properties of magnetic flux tubes are expected to scale from the solar case to that of solar-like stars. For example, it is pointed out that on giants and supergiants turbulent pressure may dominate over gas pressure as the main confining agent of the magnetic field. Arguments are also presented in favour of a highly complex magnetic geometry on very active stars. Thus the very large starspots seen in Doppler images probably are conglomerates of smaller (but possibly still sizable) spots.

Type
Session III: “Photospheric Phenomena: Results”
Information
Symposium - International Astronomical Union , Volume 176: Stellar Surface Structure , 1996 , pp. 201 - 216
Copyright
Copyright © Kluwer 1996 

References

Adam, M.G., 1990, Solar Phys. 125, 37 CrossRefGoogle Scholar
Albregtsen, F., Maltby, P., 1978, Nature 274, 41 CrossRefGoogle Scholar
Albregtsen, F., Maltby, P., 1981, Solar Phys. 71, 269 CrossRefGoogle Scholar
Bogdan, T.J., Gilman, P.A., Lerche, I., Howard, R., 1988, Astrophys. J. 327, 451 CrossRefGoogle Scholar
Brants, J.J., 1985, Solar Phys. 98, 197 CrossRefGoogle Scholar
Brants, J.J., Zwaan, C., 1982, Solar Phys. 80, 251 CrossRefGoogle Scholar
Brown, S.F., Donati, J.-F., Rees, D.E., Semel, M., 1991, Astron. Astrophys. 250, 463 Google Scholar
Bünte, M., Steiner, O., Pizzo, V., 1993, Astron. Astrophys. 268, 299 Google Scholar
Bünte, M., Saar, S.H., 1993, Astron. Astrophys. 271, 167 Google Scholar
Chapman, G.A., Cookson, A.M., Dobias, J.J., 1994, Astrophys. J. 432, 403 CrossRefGoogle Scholar
Collados, M., Martínez Pillet, V., Ruiz Cobo, B., del Toro Iniesta, J.C., Vázquez, M., 1994, Astron. Astrophys. 291, 622 Google Scholar
Donati, J.-C., 1996, these proceedings Google Scholar
Foukal, P., 1993, Solar Phys. 148, 219 CrossRefGoogle Scholar
Foukal, P., Solanki, S.K., Zirker, J., 1996, in Astrophysical Quantities , 4th Ed., Allen, C. W., Cox, A. N. (Eds.), Athlone Press, in press Google Scholar
Gray, D.F., 1975, Astrophys. J. 202, 148 CrossRefGoogle Scholar
Gray, D.F., 1988, Lectures on Spectral-Line Analysis: F, G, and K Stars , The Publisher, Arva, Ontario Google Scholar
Gray, D.F., 1992, The Observation and Analysis of Stellar Photospheres , Cambridge University Press, Cambridge Google Scholar
Grossmann-Doerth, U., Knölker, M., Schüssler, M., Solanki, S.K., 1994, Astron. Astrophys. 285 648 Google Scholar
Hasan, S.S., 1984, Astrophys. J. 285, 851 CrossRefGoogle Scholar
Hasan, S.S., 1985, Astron. Astrophys. 143, 39 Google Scholar
Hickey, J.R., Alton, B.M., Kyle, H.L., Hoyt, D., 1988, Space Sci. Rev. 48, 321 CrossRefGoogle Scholar
Hoyt, D.V., Kyle, H.L., Hickey, J.R., Maschhoff, R.H., 1992, J. Geophys. Res. 97, 51 CrossRefGoogle Scholar
Keller, C.U., 1992, Nature 359, 307 CrossRefGoogle Scholar
Keller, C.U., Deubner, F.-L., Egger, U., Fleck, B., Povel, H.P., 1994, Astron. Astrophys. 286, 626 Google Scholar
Kopp, G., Rabin, D., 1992, Solar Phys. 141, 253 CrossRefGoogle Scholar
Koutchmy, S., 1977, Astron. Astrophys. 61, 397 Google Scholar
Kurucz, R.L., 1991, in Precision Photometry: Astrophysics of the Galaxy , Davis Philip, A.G., Upgren, A.R., Janes, K.A. (Eds.), L. Davis Press, Schenectady Google Scholar
Lites, B.W., Skumanich, A., 1990, Astrophys. J. 348, 747 CrossRefGoogle Scholar
Lites, B.W., Elmore, D.F., Seagraves, P., Skumanich, A., 1993, Astrophys. J. 418, 928 CrossRefGoogle Scholar
Maltby, P., Avrett, E.H., Carlsson, M., Kjeldseth-Moe, O., Kurucz, R.L., Loeser, R., 1986, Astrophys. J. 306, 284 CrossRefGoogle Scholar
McPherson, M.R., Lin, H., Kuhn, J.R., 1992, Solar Phys. 139, 255 CrossRefGoogle Scholar
Meyer, E., Schmidt, H.U., Weiss, N.O., 1977, Monthly Notices Royal Astron. Soc. 179, 741 CrossRefGoogle Scholar
Moreno Insertis, F., 1992, in Theory of Sunspots , Thomas, J. H., N. Weiss Cambridge University Press, p. 385 (Eds.),CrossRefGoogle Scholar
Muller, R., 1983, Solar Phys. 85, 113 CrossRefGoogle Scholar
Muller, R., Keil, S.L., 1983, Solar Phys. 87, 243 CrossRefGoogle Scholar
Parker, E.N., 1975, Solar Phys. 40, 291 CrossRefGoogle Scholar
Parker, E.N., 1978, Astrophys. J. 221, 368 CrossRefGoogle Scholar
Rabin, D., 1992a, Astrophys. J. 390, L103 CrossRefGoogle Scholar
Rabin, D., 1992b, Astrophys. J. 391, 832 CrossRefGoogle Scholar
Radick, R.R., Lockwood, G.W., Baliunas, S.L., 1990, Science 247, 39 CrossRefGoogle Scholar
Roberts, B., Webb, A.R., 1978, Solar Phys. 56, 5 CrossRefGoogle Scholar
Rüedi, I., Solanki, S.K., Livingston, W., Stenflo, J.O., 1992, Astron. Astrophys. 263, 323 Google Scholar
Rüedi, I., Solanki, S.K., Mathys, G., Saar, S.H., 1996, Astron. Astrophys. to be submitted Google Scholar
Saar, S.H., 1990, in Solar Photosphere: Structure, Convection and Magnetic Fields , Stenflo, J. O. (Ed.), Kluwer, Dordrecht, IAU Symp. 138, 427 CrossRefGoogle Scholar
Saar, S.H., 1994, in Cool Stars, Stellar Systems and the Sun, VIII , Caillault, J.-P. (Ed.), Astron. Soc. Pacific Conf. Ser., Vol. 64, p. 319 Google Scholar
Saar, S.H., 1996, these proceedings Google Scholar
Saar, S.H., Linsky, J.L., 1985, Astrophys. J. 299, L47 CrossRefGoogle Scholar
Schüssler, M., 1984, Astron. Astrophys. 140, 453 Google Scholar
Schüssler, M., Caligari, P., Ferriz Mas, A., Solanki, S.K., Stix, M., 1996, Astron. Astrophys. submitted Google Scholar
Sobotka, M., 1988, Bull. Astron. Inst. Czechosl. 39, 236 Google Scholar
Sobotka, M., Bonet, J.A., Vázquez, M., 1993, Astrophys. J. 415, 832 CrossRefGoogle Scholar
Solanki, S.K., 1993, Space Sci. Rev. 61, 1 CrossRefGoogle Scholar
Solanki, S.K., 1992, in Cool Stars, Stellar Systems and the Sun, VII , Giampapa, M. S., Bookbinder, J. A. (Eds.), Astron. Soc. Pacific Conf. Ser., Vol. 26, p. 211 Google Scholar
Solanki, S.K., 1994, in The Sun as a Variable Star: Solar and Stellar Irradiance Variations , Pap, J., Fröhlich, C., Hudson, H.S., Solanki, S.K. (Eds.), Cambridge University Press, Cambridge, IAU Coll. 143, 226 Google Scholar
Solanki, S.K., 1995, in Infrared Tools for Solar Astrophysics: What's Next? , Kuhn, J. R., Penn, M. J. (Eds.), World Scientific, Singapore, p. 341 Google Scholar
Solanki, S.K., Brigljevic, V., 1992, Astron. Astrophys. 262, L29 Google Scholar
Solanki, S.K., Schmidt, H.U., 1993, Astron. Astrophys. 267, 287 Google Scholar
Solanki, S.K., Rüedi, I., Livingston, W., 1992, Astron. Astrophys. 263, 339 Google Scholar
Solanki, S.K., Zuffrey, D., Lin, H., Rüedi, I., 1996, in preparation Google Scholar
Spruit, H.C., 1979, Solar Phys. 61, 363 CrossRefGoogle Scholar
Spruit, H.C., Zwaan, C., 1981, Solar Phys. 70, 207 CrossRefGoogle Scholar
Spruit, H.C., Zweibel, E.G., 1979, Solar Phys. 62, 15 CrossRefGoogle Scholar
Steiner, O., 1995, in Solar and Galactic Magnetic Fields , Schmitt, D. (Ed.), Nachr. der Akad. der Wiss. in Göttingen, Göttingen, in press Google Scholar
Steiner, O., Grossmann-Doerth, U., Knölker, M., Schüssler, M., 1995, Rev. Mod. Astron. 8, p. 81 Google Scholar
Stellmacher, G., Wiehr, E., 1988, Astron. Astrophys. 191, 149 Google Scholar
Stenflo, J.O., 1977, in The Energy Balance and Hydrodynamics of the Solar Chromosphere and Corona , Bonnet, R.-M., Delache, Ph. (Eds.), de Bussac, G., Clermont-Ferrand, IAU Coll. 36, p. 143 CrossRefGoogle Scholar
Stenflo, J.O., 1994, Solar Magnetic Fields: Polarized Radiation Diagnostics , Kluwer, Dordrecht CrossRefGoogle Scholar
Thomas, J.H., Weiss, N., (Eds.) 1992, Sunspots: Theory and Observations , NATO ASI Series, Kluwer, Dordrecht CrossRefGoogle Scholar
Title, A.M., Topka, K.P., Tarbell, T.D., Schmidt, W., Balke, C., Scharmer, G., 1992, Astrophys. J. 393, 782 CrossRefGoogle Scholar
Topka, K.P., Tarbell, T.D., Title, A.M.: 1992, Astrophys. J. 396, 351 CrossRefGoogle Scholar
Valenti, J.A., Marcy, G.W., Basri, G., 1995, Astrophys. J. 439, 939 CrossRefGoogle Scholar
Venkatakrishnan, P., 1986, Nature 322, 156 CrossRefGoogle Scholar
Wang, J., Wang, H., Tang, F., Lee, J.W., Zirin, H., 1995, Solar Phys. 160, 277 CrossRefGoogle Scholar
Willson, R.C., Hudson, H.S., 1988, Nature 332, 810 CrossRefGoogle Scholar
Willson, R.C., Hudson, H.S., Chapman, G.A., 1991, Nature 351, 42 CrossRefGoogle Scholar
Zayer, I., Solanki, S.K., Stenflo, J.O., 1989, Astron. Astrophys. 211, 463 Google Scholar