Analysis and modelling of the δ-Scuti stars HD (ID7528) & HD (ID7613) Antonio García Hernández; Moya, A.; Suárez, J.C.; Garrido, R. et al. (Instituto de Astrofísica de Andalucía, CSIC, Spain) CoRoT Symposium, February 2009

INTRODUCTION Frequency analysis (Garrido et al. poster) Main objetive: physical characterisation stars: – High quality CoRoT data – Large number of frequencies CoRoT Symposium, February 2009

INTRODUCTION Tools: – CESAM2k (Morel): equilibrium models – GraCo (non-adiabatic effects). Moya, A. & Garrido,R. (2008,Ap&SS M) – FILOU (rotational effects second order). Suárez, J.-C. & Goupil, M.J. (2008,Ap&SS S) CoRoT Symposium, February 2009

METHODOLOGY Global parameters T eff, logg, Z ->uncertainty box in the HR diagram Equilibrium models characteristics: CESAM2k code 4000 points (ESTA recommendation) α MLT = 0.5 Diffusion (Michaud-Proffit formalism with radiative diffusion) Kurucz and Eddington atmosphere models CoRoT Symposium, February 2009

METHODOLOGY Calculate Fourier Transform ->large/small separation -> mean density, mass, age Calculate frequencies Calculate non-adiabatic observables ->unstability range (growth rate) Calculate second order rotational effects ->rotational splitting Use of multi-colour photometry and spectroscopy (LPV) CoRoT Symposium, February 2009

Calculate Fourier Transform ->large/small separation -> mean density, mass, age Calculate frequencies Calculate non-adiabatic observables ->unstability range (growth rate) Calculate second order rotational effects ->rotational splitting Use of multi-colour photometry and spectroscopy (LPV) CoRoT Symposium, February 2009 METHODOLOGY

Calculate Fourier Transform ->large/small separation -> mean density, mass, age Calculate frequencies Calculate non-adiabatic observables ->unstability range (growthrate) Calculate second order rotational effects ->rotational splitting Use ofmulti-colour photometry and spectroscopy (LPV) METHODOLOGY CoRoT Symposium, February 2009

RESULTS HD (ID7528): – δ-Scuti (mainsequence) – T eff = 7637±200 K – logg = 4.03±0.2 – [Fe/H] = -0.11±0.2 HD (ID7613): – δ-scuti (mainsequence) – T eff = 8000±200 K – logg = 4.08±0.2 – [Fe/H] = -0.32±0.2 CoRoT Symposium, February 2009

RESULTS CoRoT Symposium, February 2009 ID7613 ID7528

CoRoT Symposium, February 2009

ID7528[Fe/H] = ID7613[Fe/H] = Rejectedmodel Newmodel

CoRoT Symposium, February 2009

CONCLUSIONSFUTURE WORK CONCLUSIONS&FUTURE WORK – Usefulness of large number of frequencies: Large separation Large separation Growth rate Growth rate – Disentangle rotational splitting and small separation – Colours – Spectroscopy (LPV) CoRoT Symposium, February 2009