Reference : Towards an effective asteroseismology of solar-like stars: time-dependent convection ...
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Space science, astronomy & astrophysics
http://hdl.handle.net/2268/140183
Towards an effective asteroseismology of solar-like stars: time-dependent convection effects on pulsation frequencies
English
Grigahcène, A. [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal]
Dupret, Marc-Antoine mailto [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie >]
Sousa, S. G. [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal]
Monteiro, M. J. P. F. G. [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal; Departamento de Física e Astronomia, Faculdade de Ciências da Universidade do Porto, 4169-007 Porto, Portugal]
Garrido, R. [Instituto de Astrofísica de Andalucía, CSIC, PO Box 3004, 18080 Granada, Spain]
Scuflaire, Richard mailto [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Evol. et stabilité des étoiles et des amas d'étoiles (ESEA) >]
Gabriel, M. [Institut d'Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17-B 4000 Liège, Belgium)]
1-May-2012
Monthly Notices of the Royal Astronomical Society
422
L43
Yes
International
[en] asteroseismology ; convection ; Sun: oscillations ; stars: oscillations
[en] Since the early days of helioseismology, adiabatic models have shown their limits for a precise fitting of individual oscillation frequencies. This discrepancy, which also exists for solar-type stars, is known to originate near the surface superadiabatic convective region where the interaction between oscillations and convection is likely to have a large effect on the frequencies. We present an asteroseismic study to address the adequacy of time-dependent convection (TDC) non-adiabatic models to better reproduce the observed individual frequencies. We select, for this purpose, three solar-like stars, in addition to the Sun, to which we fit the observed frequencies in a grid of TDC non-adiabatic models. The best model selection is done by applying a maximum likelihood method. The results are compared to pure adiabatic and near-surface corrected adiabatic models. We show that, first, TDC models give very good agreement for the mode frequencies and average lifetimes. In the solar case, the frequency discrepancy is reduced to <1.75 μHz over 95 per cent of the modes considered. Secondly, TDC models give an asteroseismic insight into the usually unconstrained ad hoc stellar parameters, such as the mixing-length parameter α[SUB]MLT[/SUB].
http://hdl.handle.net/2268/140183
also: http://hdl.handle.net/2268/140185
10.1111/j.1745-3933.2012.01233.x
http://adsabs.harvard.edu/abs/2012MNRAS.422L..43G

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