Towards a precise asteroseismology of solar-like stars

A. Grigahcène, M.-A. Dupret, S. G. Sousa, M. J. P. F. G. Monteiro, R. Scuflaire

Abstract.
Two conditions are necessary for a precise probing of the physics of the stellar interior with asteroseismology. The first is related to the quality of the collected data. A major improvement has been achieved thanks to space missions, gathering unprecedented high-quality data. The second condition, no less important than the previous one, is the improvement of theoretical models able to reflect the complex physics at work in the stars, allowing for a precise interpretation of the observations. Solar like-stars have extensive convective envelopes, responsible for the excitation of their oscillations modes which occurs mostly near the top of the envelope. However, adiabatic models of the oscillations have shown their limits for a precise fitting of individual oscillation frequencies. That is known as the problem of the near-surface effects on the mode physics. Here, we present a theoretical study to address the adequacy of Time- Dependent-Convection non-adiabatic models to better reproduce the observed individual frequencies of oscillation.
Thereby the number of acceptable model solutions are significantly reduced and more precise constraints can be imposed on those models. The results obtained for specific stars match very well both the global and the seismic observables. These indicate that the accuracy of the model fitting based on seismic data is greatly improved when a more complete description of the interaction convection-pulsation is taken into account.

20th Stellar Pulsation Conference Series
Granada, Spain
setembro 2011

Tipo: Comunicação oral