The Solar Corona: White Light Polarization and Modelling of the Large Scale Electron Density Distribution

  • P. Cugnon
  • J.-R. Gabryl
Conference paper
Part of the NATO Science Series book series (ASIC, volume 558)


The corona is the outer part of the solar atmosphere, visible in white light during the total solar eclipses. As such, it appears constituted of giant loops and of streamers, extending up to several solar radii. The corona is separated from the chromosphere by a narrow transition region with very high temperature gradients. In this very thin layer, the temperature increases from about 10 000 K in the chromosphere up to millions K in the corona. Though considerable progresses have been recently made in this field, the heating of the corona remains a rather unsolved problem of the physics of the corona. This high temperature and the low density imply that the corona is constituted of highly ionized thin plasma. The temperature appears roughly stable between 10 6 and 2 10 6 K (Withbroe [1]). Hydrostatic equilibrium may be assumed for some local investigations, but the existence of the solar wind and of frequent big coronal mass ejections (CME) contradicts this assumption at larger scales.


Solar Wind Coronal Mass Ejection Solar Corona Electron Density Distribution Solar Radius 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Withbroe G.L. (1988), The temperature, mass and energy flow in the corona and inner solar wind, Astroph. Journ., 325, 442–467ADSCrossRefGoogle Scholar
  2. 2.
    Waldmeier M. (1971), The solar corona in the eleven-year cycle, Physics of the Solar Corona (Proceedings of NATO ASI held at Athens, 6–17 September 1970), ed. C.J. Macris, Reidel, Dordrecht, 130–139Google Scholar
  3. 3.
    Koutchmy S. (1986), Preprint 161, partim. Structure de la couronne solaire, Inst. Astroph. Paris, 1–13Google Scholar
  4. 4.
    Koutchmy S. and Loucif M.L. (1989), Solar cycle varations of coronal structures, Astron. Astroph. Suppl. Ser., 77, 45–66ADSGoogle Scholar
  5. 5.
    Schuster A. (1879), On the polarisation of the solar corona, Monthly Notices of the R.A.S., 40, 35–57ADSGoogle Scholar
  6. 6.
    Minnaert M. (1930), On the continuous spectrum of the corona and its polarisation, Zeitschrift für Astroph., 1, 209–236ADSzbMATHGoogle Scholar
  7. 7.
    Baumbach S. (1937), Strahlung, Ergiebkeit und Elektronendicht der Sonnekorona, Astronomische Nachrichten, 263, 121–134ADSCrossRefGoogle Scholar
  8. 8.
    van de Hulst H.C. (1950), The electron density of the solar corona, Bull. Astron. Inst. Netherlands, 11, 135–150ADSGoogle Scholar
  9. 9.
    Saito K. (1970), A non-spherical axisymmetric model of the solar K corona of the minimum type, Ann. Tokyo Astr. Obs., 13, 53–120ADSGoogle Scholar
  10. 10.
    Gabryl J.-R. (1994), Développement d’un modèle de densité électronique de la couronne solaire, Mémoire de DEA, Université de Liège, BelgiumGoogle Scholar
  11. 11.
    Perry R.M. and Altschuler M.D. (1973), Improved three-dimensional mapping of the electron density distribution of the solar corona, Sol. Phys., 28, 435–456ADSCrossRefGoogle Scholar
  12. 12.
    Koutchmy S. (1992), Preprint 404, partim. Allen – 3rd edition revised by Serge Koutchmy, Inst. Astroph. Paris, 1–3Google Scholar
  13. 13.
    Badalyan O.G. (1986), Polarization of the white-light corona under hydrostatic density distribution, Astron. Astroph., 169, 305–312ADSGoogle Scholar
  14. 14.
    Gulyaev R.A. (1992),Eclipse observations of the outer corona and the SOHO mission, ESA-SP 348, 133–136ADSGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2000

Authors and Affiliations

  • P. Cugnon
    • 1
  • J.-R. Gabryl
    • 1
  1. 1.Royal Observatory of BelgiumBruxellesBelgium

Personalised recommendations