It is pointed out that the time scale of energy transport in the Sun is the Kelvin–Helmholtz time scale, of order 3×107 years, roughly 100 times longer than the photon-diffusion time estimated by Mitalas and Sills (1992). The difference corresponds to a factor Ugas/Urad, the ratio of thermal energy density to radiation energy density. Thus the heat transport, even when mediated by photons, is slowed down by the large heat capacity of the star. A numerical example calculation is presented.
KeywordsRadiation Energy Density Heat Capacity Thermal Energy Heat Transport
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- Kippenhahn, R. and Weigert, A.: 1990, Stellar Structure and Evolution, Springer-Verlag, Berlin.Google Scholar
- Kippenhahn, R., Weigert, A., and Hofmeister, E.: 1967, Meth. Comp. Phys. 7, 129.Google Scholar
- Lang, K. R.: 2001, The Cambridge Encyclopedia of the Sun, Cambridge University Press, Cambridge.Google Scholar
- Press, W. H.: 1986, in P. A. Sturrock, T. E. Holzer, D. M. Mihalas, and R. K. Ulrich (eds.), Physics of the Sun, D. Reidel Publ. Co., Dordrecht, Holland.Google Scholar
- Stix, M.: 2002, The Sun, an Introduction, 2nd ed., Springer-Verlag, Berlin.Google Scholar