Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-20T06:52:09.776Z Has data issue: false hasContentIssue false
  • English
  • Français

Small-Scale Dissipative Processes in Stellar Atmospheres

Published online by Cambridge University Press:  30 March 2016

J. W. Leibacher  and
R. F. Stein
J. W. Leibacher
Affiliation:
Space Astronomy Group, Lockheed Palo Alto Research Laboratory, Palo Alto, California
R. F. Stein
Affiliation:
Department of Astronomy and Astrophysics, Michigan State University East Lansing, Michigan

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 outer atmospheres of stars must be heated by some non-thermal energy flux to produce chromospheres and coronae. We discuss processes which convert the non-thermal energy flux of organized, macroscopic motions into random, microscopic (thermal) motions. Recent advances in our description of the chromosphere velocity field suggest that the acoustic waves observed there transmit very little energy, and hence are probably incapable of heating the upper chromosphere and corona. The apparent failure of this long held mechanism and the growing appreciation of the importance of strong magnetic fields in the chromosphere and corona have led to hypotheses of heating by the dissipation of currents (both oscillatory and quasi-steady). This follows discoveries in laboratory and ionospheric plasmas and work on solar flares, that instabilities can concentrate currents into thin high current density filaments where they dissipate rapidly.

Type
Joint Discussion
Information
Highlights of Astronomy , Volume 5: Highlights of Astronomy. As presented at the XVIIth General Assembly of the IAU, 1979 , 1980 , pp. 581 - 590
Copyright
Copyright © Cambridge University Press 1980

References

1. Athay, R.G. and White, O.R.: 1978, Astrophys, J. 226, pp. 1135: Chromospheric and Coronal Heating by Sound Waves.Google Scholar
2. Bateman, G.: 1978, “MHD Instabilities” (Cambridge: MIT)Google Scholar
3. Bruner, E.C.: 1977, Astrophys. J. 226, pp. 1140–1146: Dynamics of the Solar Transition Zone. Google Scholar
4. Cram, L.E.: 1977, Aston. Astrophys. 59, pp. 151–159: On the Heating of the Solar Chromosphere. Google Scholar
5. Cram, L. E and Ulmschneider, P.: 1978, Astron. Astrophys 62, pp. 239: Observational Tests of the Shock Heating Theory for Late-Type Stellar Chromospheres. Google Scholar
6. Derby, N.F.: 1978, Astrophys. J. 224, pp. 1013: Modulational Instability of Finite Amplitude Circularly Polarized Alfven Waves. Google Scholar
7. Drake, J.F. and Lee, Y.C. 1977, Phys. Fluids, 20, pp. 1341: Kinetic Theory of Tearing Instabilities. Google Scholar
8. Hollweg, J.V. 1980, in “Proceedings of the Skylab Active Region Workshop”, Orrai, F.Q., Ed., Preprint: Mechanisms of Energy Supply. Google Scholar
9. Leibacher, J.W. 1977, in “Proc. OSO-8 Workshop”, Hansen, E. and Schaffner, S. (Eds.), Boulder, Colorado, pp. 311–339: Theoretical Aspects of the ZOO Second and Related Oscillations of the Solar Atmosphere. Google Scholar
10. Linsky, J.L. and Ayres, T.R. 1978, Astrophys. J. 220, pp. 619: Stellar Model Chromospheres. VI. Empirical Estimates of the Chromospheric Radiative Losses of Late Type Stars. Google Scholar
11. Melrose, D.B. 1977, Aust. J. Phys. 30, pp. 495–509: Mode Coupling in the Solar Corona. III. Alfven and Magnetoaaoustic Waves. CrossRefGoogle Scholar
12. Osterbrock, D.E. 1971, Astrophys. J. 134, pp. 347–388: The Heating of the Solar Chromosphere, Plages and Corona by Magneto-hydodynamia Waves. Google Scholar
13. Papadopoulos, K. 1977, Rey. Geophys. and Spa. Phys. 15, pp. 113: A Review of Anomalous Resistivity for the Ionosphere. Google Scholar
14. Parker, E.N. 1974, Astrophys. J. 191, pp. 245–254: The Dynamical Properties of Twisted Ropes of Magnetic Fields and the vigor of New Active Regions on the Sun. Google Scholar
15. Peckover, R.S. and Weiss, N.O. 1978, Mon. Not. Roy. Astron. Soc. 182, pp. 189: On the Dynamic Interaction Between Magnetic Fields and Convection. Google Scholar
16. Renzini, A., Cacciari, C., Ulmschneider, P., and Schmitz, F. 1977, Astron. Astrophys. 61, pp. 39: Theoretical Chromospheres of Late Type Stars. I. Acoustic Energy Generation. Google Scholar
17. Rosner, R., Golub, L., Coppi, B., and Vaiana, G.S. 1978, Astrophys. J. 222, pp. 317: Heating of Coronal Plasma by Anomalous Current Dissipation. Google Scholar
18. Rosner, R., Tucker, W.H., and Vaiana, G.S. 1978, Astrophys. J. 220, pp. 643: Dynamics of the Quiescent Solar Corona. Google Scholar
19. Spicer, D. and Brown, J.C. 1980, in “The Sun as a Star”, Jordan, S. (Ed.), Preprint: Solar Flare Theory: A Review. Google Scholar
20. Stein, R.F., and Leibacher, J.W. 1974, Ann. Rev. Astron. Astrophys. 12, pp. 407–435: Waves in the Solar Atmosphere Google Scholar
21. Stein, R.F. and Leibacher, J.W. 1979, Proceedings of I.A.U. Colloquium 51 “Turbulence in Stars”, Gray, D. (Ed.), in press: Mechanical Energy Transport. Google Scholar
22. Stein, R.F. and Leibacher, J.W. 1980, in “The Sun as a Star”, Jordan, S., Ed., In preparation: Generation of Waves. Google Scholar
23. Uchida, Y. and Kaburaki, O. 1974, Solar Phys. 35, pp. 451–466: Excess Heating of Corona and Chromosphere above Magnetic Regions by Non-Linear Waves. CrossRefGoogle Scholar
24. Ulmschneider, P., Schmitz, F., Kalkofen, W. and Bohn, H.U. 1978, Astron. Astrophys. 70, pp. 787–800: Acoustic Waves in the Solar Atmosphere. V. On the Chromospheric Temperature Rise. Google Scholar
25. Wentzel, D.G. 1978, Rev. Geophys. Spa. Sci. 16, pp. 757–761: Heating of the Solar Corona. Google Scholar
26. Zirker, J.B. 1979, Proceedings of the 17th Aerospace Sciences Meeting, New Orleans: Solar Hydrodynamics. Google Scholar