Impact of the physical processes in the modeling of HD49933

TL;DR

This study examines how different physical processes and modeling parameters, such as diffusion, rotation, and convection, influence the seismic modeling of the star HD49933, using advanced computational tools.

Contribution

It provides a quantitative analysis of the effects of sophisticated physics on the asteroseismic modeling of HD49933, highlighting the importance of composition and diffusion.

Findings

Mass and composition uncertainties significantly affect seismic variables.

Surface phase shift derivative helps determine helium content.

Seismic variables are sensitive to assumed solar composition and diffusion.

Abstract

Context : On its asteroseismic side, the initial run of CoRoT was partly devoted to the solar like star HD49933.The eigenmodes of this F dwarf have been observed with unprecedented accuracy. Aims : We investigate quantitatively the impact of changes in the modeling parameters like mass and composition. More importantly we investigate how a sophisticated physics affects the seismological picture of HD49933. We consider the effects of diffusion, rotation and the changes in convection efficiency. Methods : We use the CESAM stellar evolution code coupled to the ADIPLS adiabatic pulsation package to build secular models and their associated oscillation frequencies. We also exploited the hydrodynamical code STAGGER to perform surface convection calculations. The seismic variables used in this work are : the large frequency separation, the derivative of the surface phase shift,and the eigenfrequencies $\rm \nu_{\ell=0,n=14}$ and $\rm \nu_{\ell=0,n=27}$. Results : Mass and uncertainties on the composition have much larger impacts on the seismic variables we consider than the rotation. The derivative of the surface phase shift is a promising variable for the determination of the helium content. The seismological variables of HD49933 are sensitive to the assumed solar composition and also to the presence of diffusion in the models.