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Coronal and Chromospheric Structures in AR LAC: I. Data and Models

Published online by Cambridge University Press:  04 August 2017

D.M. Gibson
Affiliation:
Dept. of Physics, New Mexico Tech, Socorro, NM, USA
F.M. Walter
Affiliation:
JILA, U. of Colorado, Boulder, CO, USA
G.S. Basri
Affiliation:
SSL, U. of California at Berkeley, Berkeley, CA, USA

Extract

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Traditionally stellar sizes and shapes have been determined by analyzing the optical light curves of eclipsing binaries. Now it is possible to extend our knowledge to structures above the photosphere by making similar observations at X-ray, UV, and radio wavelengths. We report the first such observations, together with their geometrical and physical interpretation, which allow us to determine coronal and chromospheric properties of the stars in the RS CVn binary AR Lac. In this paper we discuss the properties of the system, Einstein observations which provide a reasonably good X-ray light curve, IUE data which enable us to tie the inferred coronal features to the surfaces, and radio observations which allow us to separate geometric and intrinsic variations by acting as a flare monitor. We also discuss the construction of simple coronal model which, when applied to the X-ray light curve, yields the sizes and shapes of the coronae in this system. In another paper (Paper II: Walter, Gibson, and Basri, 1982), the geometrical properties of the coronae are discussed and used to determine the physical conditions within.

Type
IV. The Role of Magnetic Fields in the Structure and Energy Balance of Stellar Atmospheres
Copyright
Copyright © Reidel 1983 

References

Chambliss, C.R.: 1976, Publ. Astron. Soc. Pacific 88, p. 762.CrossRefGoogle Scholar
Feldman, P.A.: 1980, private communication.Google Scholar
Gibson, D.M. and Hjellming, R.M.: 1974, Publ. Astron. Soc. Pacific 85, p. 682.Google Scholar
Hall, D.S.: 1976, in “Multiple Periodic Variable Stars”, ed. Fitch, W.S. (Dordrecht: Reidel).Google Scholar
Hall, D.S.: 1980, private communication.Google Scholar
Swank, J.H. and White, N.E.: 1980, in “Cool Stars, Stellar Systems, and the Sun”, ed. Dupree, A.K. (Cambridge: SAO).Google Scholar
Walter, F.M., Gibson, D.M., and Basri, G.S.: 1983, in IAU Colloquium No. 71.Google Scholar
Walter, F.M., Cash, W., Charles, P., Bowyer, S.: 1980, Astrophys. J. 236, p. 212.CrossRefGoogle Scholar