Skip to main content
SpringerLink
Log in

On the possibility of constructing a radiative sunspot model in magnetohydrostatic equilibrium

  • Published:
Solar Physics Aims and scope Submit manuscript

Abstract

It is currently believed that it is impossible to construct a radiative sunspot model in magnetohydrostatic equilibrium unless magnetic fields below the surface are excessively large (> 100 kG). This belief is based on results obtained using the mixing length theory of convection. We wish to point out that by using a different theory of convection, due to Öpik (1950), it is possible to compute a radiative sunspot model in which the field becomes no greater than 9000 G. By applying two boundary conditions, (i) depth of spot equals depth of convection zone, (ii) magnetic field has zero gradient at the base of the spot, we show that a radiative spot has a unique effective temperature for a given Wilson depression, Δ. For Δ = 650 km, we find T e = 3800K ; for Δ = 150 km, T e = 3950K. According to our model, spots having T e cooler than these values should not exist.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Bray, R. J. and Loughhead, R. E.: 1964, Sunspots, J. Wiley & Sons, Inc., New York, p. 125.

    Google Scholar 

  • Chitre, S. M.: 1963, Monthly Notices Roy. Astron. Soc. 126, 431.

    Google Scholar 

  • Deinzer, W.: 1965, Astrophys. J. 141, 548.

    Google Scholar 

  • Gough, D. O. and Tayler, R. J.: 1966, Monthly Notices Roy. Astron. Soc. 133, 85.

    Google Scholar 

  • Hall, D. N. B. and Noyes, R. W.: 1972, Paper Presented at the Meeting of the Solar Physics Division of the American Astronomical Association, University of Maryland, April, 1972.

  • Lykoudis, P.: 1971, Bull. Am. Astron. Soc. 3, 461; also preprint, May 1972.

    Google Scholar 

  • Moss, D. L. and Tayler, R. J.: 1969, Monthly Notices Roy. Astron. Soc. 145, 217.

    Google Scholar 

  • Mullan, D. J.: 1971a, Monthly Notices Roy. Astron. Soc. 154, 467.

    Google Scholar 

  • Mullan, D. J.: 1971b, Irish Astron. J. 10, 12.

    Google Scholar 

  • Mullan, D. J.: 1972, Nature Phys. Sci. 235, 58.

    Google Scholar 

  • Öpik, E. J.: 1950, Monthly Notices Roy. Astron. Soc. 110, 559.

    Google Scholar 

  • Rossbach, A. and Schröter, E. H.: 1970, Solar Phys. 12, 95.

    Google Scholar 

  • Schlüter, A. and Temesvary, S.: 1958, in B. Lehnert (ed.)., Cosmical Electrodynamics, Cambridge Univ. Press, p. 263.

  • Schröter, E. H.: 1971, in R. Howard (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43, 167.

  • Stellmacher, G. and Wiehr, E.: 1972, Astron. Astrophys. 19, 293.

    Google Scholar 

  • Yun, H. S.: 1970, Astrophys. J. 162, 970.

    Google Scholar 

  • Zwaan, C.: 1968, Ann. Rev. Astron. Astrophys. 6, 135.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Bartol Research Foundation of the Franklin Institute, 19081, Swarthmore, Pa., U.S.A.

    D. J. Mullan

Authors
  1. D. J. Mullan
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Mullan, D.J. On the possibility of constructing a radiative sunspot model in magnetohydrostatic equilibrium. Sol Phys 30, 75–81 (1973). https://doi.org/10.1007/BF00156175

Download citation

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00156175

Keywords

Search

Navigation