EDP Sciences
Free access
Volume 390, Number 3, August II 2002
Page(s) 1115 - 1118
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20020749

A&A 390, 1115-1118 (2002)
DOI: 10.1051/0004-6361:20020749

The age of the Sun and the relativistic corrections in the EOS

A. Bonanno1, H. Schlattl2, 3 and L. Paternò3

1  INAF - Osservatorio Astrofisico di Catania, Città Universitaria, 95123 Catania, Italy
2  Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD, UK
3  Dipartimento di Fisica e Astronomia dell'Università, Sezione Astrofisica, Città Universitaria, 95123 Catania, Italy

(Received 18 April 2002 / Accepted 13 May 2002)

We show that the inclusion of special relativistic corrections in the revised OPAL and MHD equations of state has a significant impact on the helioseismic determination of the solar age. Models with relativistic corrections included lead to a reduction of about $0.05{-}0.08 \; {\rm Gyr}$ with respect to those obtained with the old OPAL or MHD EOS. Our best-fit value is $t_{\rm seis} = (4.57 \pm 0.11) \; {\rm Gyr}$ which is in remarkably good agreement with the meteoritic value for the solar age. We argue that the inclusion of relativistic corrections is important for probing the evolutionary state of a star by means of the small frequency separations $\delta\nu_{{\ell,n}}=\nu_{{\ell,n}}-\nu_{{\ell+2,n-1}}$, for spherical harmonic degrees $\ell = 0,1$ and radial order $n \gg
\ell$ .

Key words: Sun: interior -- Sun: oscillations -- equation of state

Offprint request: A. Bonanno, abo@ct.astro.it

© ESO 2002