Solar Physics

, Volume 212, Issue 1, pp 3–6

On the time scale of energy transport in the sun

  • Michael Stix

DOI: 10.1023/A:1022952621810

Cite this article as:
Stix, M. Sol Phys (2003) 212: 3. doi:10.1023/A:1022952621810


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.

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • Michael Stix
    • 1
  1. 1.Kiepenheuer-Institut für SonnenphysikFreiburgGermany