Abundance Analysis of α Centauri A

Abstract

The α centauri system is a reference in stellar physics. The two components, α Cen A (G2V) and α Cen B (K1V), have been extensively studied because of their proximity (1.3pc) and similarity to the Sun. The discovery of solar-like oscillations (Bouchy & Carrier 2002) and the recent interferometric measurements (Kervella et al. 2003) make this system one of the best constrained and therefore one of the most interesting to test both stellar evolution and atmospheric models. The chemical composition of this metal-rich system is still debated ([Fe/H] ≈ +0.1 to +0.2 dex) and is a source of uncertainty in asteroseismic diagnostics. In this work, we propose to improve the Iron abundance by the use of realistic 3D radiative hydrodynamical (RHD) simulations. We present preliminary results for α Cen A and found significant smaller overabundance. This result agrees well with pulsation data.