Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-26T19:47:28.321Z Has data issue: false hasContentIssue false

The Large-Scale Structure of the Corona

Published online by Cambridge University Press:  30 March 2016

Jack B. Zirker*
Affiliation:
Sacramento Peak Observatory*, Sunspot, New Mexico, USA

Extract

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 solar corona serves as a prototype of the outer atmospheres of all cool stars. Because of its nearness we can study this prototype in more detail than any other example. Considerable progress has been made recently in understanding how the large scale structure of the solar corona controls the genesis of the solar wind and the distribution of slow and fast wind streams throughout the three-dimensional space surrounding the sun. In this review we will discuss some of the progress made in this field during the last few years. We will emphasize the observational data and the inferences that can be made more or less directly from them. T. Holzer will discuss the theoretical aspects of stellar wind acceleration in another paper in this symposium.

The large scale structures of the solar corona consist essentially of three kinds: streamers, active regions and coronal holes. Figure 1 is a familiar photograph of the solar corona, obtained in white light at the total eclipse of 30 June 1973 by the High Altitude Observatory. The streamers are the petal-like structures extending out from the black lunar limb. They taper to narrow radial spikes that have been traced out as far as 10-12 solar radii (Keller, 1979). Daily measurements of the white light corona at the Mauna Loa Observatory (Hundhausen et al. 1979) and the Pic-du-Midi Observatory (Dollfus et al., 1977) since 1965 show that the streamers are fan-shaped structures that may extend 120° in solar longitude. We see them in various perspectives at the solar limb.

Type
Joint Discussion
Copyright
Copyright © Cambridge University Press 1980

References

Altschuier, M.D.: 1974, in Newkirk, G. (ed.)> Coronal Disturbances IAU Symposium #57, Reidel Publishing Co., Dordrecht, p. 3.Google Scholar
Athay, R.G.: 1966, Astrophys. J. 145, 784.Google Scholar
Athay, R.G.: 1976, The Solar Chromosphere and Corona: Quiet Sun, Reidel Publishing Co., Dordrecht, p. 504.Google Scholar
Bohlin, J.D.: 1970, Solar Phys. 13, 153.Google Scholar
Bohlin, J.D.: 1977, in Zirker, J.B. (ed.), Coronal Holes and High Speed Wind Streams, Colorado Associated University Press, Boulder, p. 27.Google Scholar
Broussard, R.M., Sheeley, N.R., Tousey, R. and Underwood, J.H.: 1978, Solar Phys. 56, 161.Google Scholar
Dollfus, A. and Martres, J.-J.: 1977, Solar Phys. 53, 449.Google Scholar
Hundhausen, A.J.: 1977, in Zirker, J.B. (ed.), Coronal Holes and High Speed Wind Streams, Colorado Associated University Press, Boulder, p. 225.Google Scholar
Hundhausen, A.F., Hansen, R.T., Hansen, S.F.: 1979, “Coronal Evolution during Sunspot Cycle 20: K Coronameter Data,” (in preparation).Google Scholar
Keller, C.F.: 1979 (private communication).Google Scholar
Kopp, R.A. and Holzer, T.E.: 1976, Solar Phys. 49, 43.CrossRefGoogle Scholar
Krieger, A.S., Timothy, A.F. and Roelof, E.C.: 1973, Solar Phys. 29, 505.CrossRefGoogle Scholar
Levine, R.H., Altschuier, M.D., Harvey, J.W. and Jackson, B.V.: 1977, Astrophys. J. 215, 636.Google Scholar
Mariska, J.T.: 1976, Bul. Am. Astron. Soc. 8, 338.Google Scholar
Munro, R.H. and Jackson, B.V.: 1977, Astrophys. J. 213, 874.Google Scholar
Munro, R.H. and Withbroe, G.L.: 1972, Astrophys. J. 176, 511.Google Scholar
Newkirk, G.: 1967, Ann. Rev. Astron. Astrophys. 5, 213.Google Scholar
Pneuman, G.W.: 1979, Astrophys. J. (in press.)Google Scholar
Pneuman, G.W. and Kopp, R.A.: 1970, Solar Phys. 13, 176.Google Scholar
Sheeley, N.R. and Harvey, J.W.: 1978, Solar Phys. 59, 159.Google Scholar
Withbroe, G.L.: 1970, Solar Phys. 11, 42.Google Scholar
Withbroe, G.L. and Noyes, R.W.: 1977, Ann. Rev. Astron. Astrophys. 15, 363.Google Scholar