Challenges for asteroseismic analysis of Sun-like stars

Chaplin, W. J.; Houdek, G.; Appourchaux, T.; Elsworth, Y.; New, R.; Toutain, T.

doi:10.1051/0004-6361:200809695

Cited by 86 publications

(80 citation statements)

References 33 publications

(54 reference statements)

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“…We conclude that the maximum of H is determined by the minimum of Θ 2 and corresponds to the plateau of the line widths. In other words, the depression (plateau) of the damping rates η is responsible for the presence of a maximum in the power spectrum, in agreement with Chaplin et al (2008).…”

Section: Height Maximum In the Power Spectrumsupporting

confidence: 82%

“…Chaplin et al (2008), using a theoretical approach, pointed out that in the solar case ν max coincides with the plateau of the linewidth variation with frequency. We will confirm this result using observations from the GOLF instrument in the solar case.…”

Section: Introductionmentioning

confidence: 96%

“…Kjeldsen & Bedding 1995;Chaplin et al 2008Chaplin et al , 2009Stello et al 2009a) using ground-based data. More recently, the spacemissions CoRoT and Kepler confirmed those results by providing accurate and homogeneous measurements for a large sample of stars from red giants to main-sequence stars (e.g., Mosser et al 2010).…”

Section: Introductionmentioning

confidence: 99%

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The underlying physical meaning of theν_max − ν_crelation

Belkacem

Goupil

Dupret

et al. 2011

A&A

265

287

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Asteroseismology of stars that exhibit solar-like oscillations are enjoying a growing interest with the wealth of observational results obtained with the CoRoT and Kepler missions. In this framework, scaling laws between asteroseismic quantities and stellar parameters are becoming essential tools to study a rich variety of stars. However, the physical underlying mechanisms of those scaling laws are still poorly known. Our objective is to provide a theoretical basis for the scaling between the frequency of the maximum in the power spectrum (ν max ) of solar-like oscillations and the cut-off frequency (ν c ). Using the SoHO GOLF observations together with theoretical considerations, we first confirm that the maximum of the height in oscillation power spectrum is determined by the so-called plateau of the damping rates. The physical origin of the plateau can be traced to the destabilizing effect of the Lagrangian perturbation of entropy in the upper-most layers, which becomes important when the modal period and the local thermal relaxation time-scale are comparable. Based on this analysis, we then find a linear relation between ν max and ν c , with a coefficient that depends on the ratio of the Mach number of the exciting turbulence to the third power to the mixing-length parameter.

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Section: Height Maximum In the Power Spectrumsupporting

confidence: 82%

Section: Introductionmentioning

confidence: 96%

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The underlying physical meaning of theν_max − ν_crelation

Belkacem

Goupil

Dupret

et al. 2011

A&A

265

287

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“…We consider mode lifetimes computed from the grid of stellar models used by Chaplin et al (2008) with measured mode lifetimes from 12 solar-like stars, sub-giants and giants.…”

Section: Datamentioning

confidence: 99%

“…Padova isochrones (Bonatto et al 2004;Girardi et al 2002Girardi et al , 2004 were used to specify the primary characteristics of each model, i.e., mass M, radius R, effective temperature T eff , and luminosity L. The composition was fixed at X = 0.7 and Z = 0.019 for all models. In order to estimate mode lifetimes for each model Chaplin et al (2008) then performed stellar equilibrium and pulsation computations, as described in Balmforth (1992), Houdek et al (1999), and Chaplin et al (2005). The pulsation computations required estimates of M, T eff , L and the composition as input.…”

Section: Datamentioning

confidence: 99%

Mode lifetimes of stellar oscillations

Chaplin¹,

Houdek

Karoff³

et al. 2009

A&A

Self Cite

105

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Context. Successful inference from asteroseismology relies on at least two factors: that the oscillations in the stars have amplitudes large enough to be clearly observable, and that the oscillations themselves be stable enough to enable precise measurements of mode frequencies and other parameters. Solar-like p modes are damped by convection, and hence the stability of the modes depends on the lifetime. Aims. We seek a simple scaling relation between the mean lifetime of the most prominent solar-like p modes in stars, and the fundamental stellar parameters. Methods. We base our search for a relation on the use of stellar equilibrium and pulsation computations of a grid of stellar models, and the first asteroseismic results on lifetimes of main-sequence, sub-giant and red-giant stars. Results. We find that the mean lifetimes of all three classes of solar-like stars scale like T −4 eff (where T eff is the effective temperature). When this relation is combined with the well-known scaling relation of Kjeldsen & Bedding for mode amplitudes observed in narrowband intensity observations, we obtain the unexpected result that the height (the maximum power spectral density) of mode peaks in the frequency power spectrum scales as g −2 (where g is the surface gravity). As it is the mode height (and not the amplitude) that fixes the S/N at which the modes can be measured, and as g changes only slowly along the main sequence, this suggests that stars cooler than the Sun might be as good targets for asteroseismology as their hotter counterparts. When observations are instead made in Doppler velocity, our results imply that mode height does increase with increasing effective temperature.

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