The Nonhomologous Nature of Solar Diameter Variations

Sabatino Sofia (1) , Sarbani Basu (1) , Pierre Demarque (1) , Linghuai Li (1) , Gérard Thuillier (2)

1 Department of Astronomy [New Haven]
2 SA - Service d'aéronomie

We show in this Letter that the changes of the solar diameter in response to variations of large-scale magnetic fields and turbulence are not homologous. For the best current model, the variation at the photospheric level is over 1000 times larger than the variation at a depth of 5 Mm, which is about the level at which f-mode solar oscillations determine diameter variations. This model is supported by observations that indicate larger diameter changes for high-degree f-modes than for low-degree f-modes, since the energy of the former is concentrated at shallower layers than the latter.

Domaines: Astrophysique [astro-ph]

Sabatino Sofia, Sarbani Basu, Pierre Demarque, Linghuai Li, Gérard Thuillier. The Nonhomologous Nature of Solar Diameter Variations. The Astrophysical Journal, 2005, 432, pp.L147-L150. ⟨10.1086/498068⟩. ⟨hal-00078977⟩