G. Doǧan, I. M. Brandão, T. R. Bedding, J. Christensen-Dalsgaard, M. S. Cunha, H. Kjeldsen
Abstract
We present the results of modelling the subgiant star β Hydri using seismic observational constraints. We have computed several grids of stellar evolutionary tracks using the Aarhus STellar Evolution Code (ASTEC, Christensen-Dalsgaard in Astrophys. Space Sci. 316:13, 2008a), with and without helium diffusion and settling. For those models on each track that are located at the observationally determined position of β Hydri in the Hertzsprung-Russell (HR) diagram, we have calculated the oscillation frequencies using the Aarhus adiabatic pulsation package (ADIPLS, Christensen-Dalsgaard in Astrophys. Space Sci. 316:113, 2008b). Applying the near-surface corrections to the calculated frequencies using the empirical law presented by Kjeldsen et al. (Astrophys. J. 683:L175, 2008), we have compared the corrected model frequencies with the observed frequencies of the star. We show that after correcting the frequencies for the near-surface effects, we have a fairly good fit for both l = 0 and l = 2 frequencies. We also have good agreement between the observed and calculated l = 1 mode frequencies, although there is room for improvement in order to fit all the observed mixed modes simultaneously.
Keywords
Beta Hydri - Solar-like oscillations
Astrophysics and Space Science
Volume 328, Page 101
2010 July
