* Astronomy

Title: Precise Modelling of the Exoplanet Host Star and CoRoT Main Target HD 52265
Authors: M. E. Escobar, S. Théado S. Vauclair, J. Ballot, S. Charpinet, N. Dolez, A. Hui-Bon-Hoa, G. Vauclair, L. Gizon, S. Mathur, P. O. Quirion, T. Stahn

This paper presents a detailed and precise study of the characteristics of the Exoplanet Host Star and CoRoT main target HD 52265, as derived from asteroseismic studies. The results are compared with previous estimates, with a comprehensive summary and discussion. The basic method is similar to that previously used by the Toulouse group for solar-type stars. Models are computed with various initial chemical compositions and the computed p-mode frequencies are compared with the observed ones. All models include atomic diffusion and the importance of radiative accelerations is discussed. Several tests are used, including the usual frequency combinations and the fits of the échelle diagrams. The possible surface effects are introduced and discussed. Automatic codes are also used to find the best model for this star (SEEK, AMP) and their results are compared with that obtained with the detailed method. We find precise results for the mass, radius and age of this star, as well as its effective temperature and luminosity. We also give an estimate of the initial helium abundance. These results are important for the characterisation of the star-planet system.

Read more (109kb, PDF)