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We extend semi-analytical computations of excitation rates for solar oscillation modes to those of other solar-like oscillating stars to compare them with recent observations. Numerical 3D simulations of surface convective zones of several…

Astrophysics · Physics 2009-11-11 R. Samadi , D. Georgobiani , R. Trampedach R. , M. -J. Goupil , R. F. Stein , A. Nordlund

We have studied the statistical properties of the energy of individual acoustic modes, extracted from 310 days of GOLF data near the solar minimum. The exponential distribution of the energy of each mode is clearly seen. The modes are found…

The development of space-borne missions has significantly improved the quality of the measured spectra of solar-like oscillators. Their $p$-mode line profiles can now be resolved, and the asymmetries inferred for a variety of stars other…

Solar and Stellar Astrophysics · Physics 2021-01-04 J. Philidet , K. Belkacem , H. -G. Ludwig , R. Samadi , C. Barban

Hydrodynamical, 3D simulations of the outer layers of the Sun and Alpha Cen A are used to obtain constraints on the properties of turbulent convection in such stars. These constraints enable us to compute - on the base of a theoretical…

Astrophysics · Physics 2007-05-23 R. Samadi , M. J. Goupil , F. Baudin , D. Georgobiani , R. Trampedach , R. Stein , A. Nordlund

From the seismic data obtained by CoRoT for the star HD 49933 it is possible, as for the Sun, to constrain models of the excitation of acoustic modes by turbulent convection. We compare a stochastic excitation model described in Paper I…

Solar and Stellar Astrophysics · Physics 2010-01-26 R. Samadi , H. -G. Ludwig , K. Belkacem , M. J. Goupil , O. Benomar , B. Mosser , M. -A. Dupret , F. Baudin , T. Appourchaux , E. Michel

The excitation of solar and solar-like g modes in non-relativistic stars by arbitrary external gravitational wave fields is studied starting from the full field equations of general relativity. We develop a formalism that yields the…

Solar and Stellar Astrophysics · Physics 2010-10-25 D. M. Siegel , M. Roth

The observed solar p-mode velocity power spectra are compared with theoretically calculated power spectra over a range of mode degree and frequency. The shape of the theoretical power spectra depends on the depth of acoustic sources…

Astrophysics · Physics 2009-10-30 Pawan Kumar , Sarbani Basu

We demonstrate autoparametric excitation of two distinct sub-harmonic mechanical modes by the same driven mechanical mode corresponding to different drive frequencies within its resonance dispersion band. This experimental observation is…

Pattern Formation and Solitons · Physics 2017-10-11 Adarsh Ganesan , Cuong Do , Ashwin Seshia

Successful inference from asteroseismology relies on at least two things: 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…

Solar and Stellar Astrophysics · Physics 2015-05-13 W. J. Chaplin , G. Houdek , C. Karoff , Y. Elsworth , R. New

Observations show that the solar p-mode frequencies change with the solar cycle. The horizontal-phase-velocity dependence of the relative frequency change, scaled by mode mass, provides depth information on the perturbation in the solar…

Astrophysics · Physics 2009-11-10 Dean-Yi Chou , Alexander Serebryanskiy

The aim of this work is to provide new insights on the dynamics associated to the resonances which arise as a consequence of the coupling of the effect due to the oblateness of the Earth and the Solar Radiation Pressure (SRP) effect for an…

Earth and Planetary Astrophysics · Physics 2022-12-14 Roberto Paoli

We compute the p-mode oscillation frequencies and frequency splittings that arise in a two-dimensional model of the Sun that contains toroidal magnetic fields in its interior.

Astrophysics · Physics 2008-10-29 Linghuai Li , Sarbani Basu , Sabatino Sofia , Pierre Demarque

Thermal noise and harmonic forcing have recently been shown to cooperatively excite sine-Gordon breathers robust to dissipation. Such a phenomenon has been found assuming a Gaussian noise source, delta-correlated both in time and space. In…

Pattern Formation and Solitons · Physics 2025-02-13 Giovanni Di Fresco , Duilio De Santis , Claudio Guarcello , Bernardo Spagnolo , Angelo Carollo , Davide Valenti

We focus on the influence of the Coriolis acceleration on the stochastic excitation of oscillation modes in convective regions of rotating stars. Our aim is to estimate the asymmetry between excitation rates of prograde and retrograde…

Solar and Stellar Astrophysics · Physics 2015-05-14 K. Belkacem , S. Mathis , M. J. Goupil , R. Samadi

We make predictions of the detectability of low-frequency p modes. Estimates of the powers and damping times of these low-frequency modes are found by extrapolating the observed powers and widths of higher-frequency modes with large…

Astrophysics · Physics 2009-11-13 A. M. Broomhall , W. J. Chaplin , Y. Elsworth , S. T. Fletcher

Recent observations indicate that solar p-mode line profiles are not exactly Lorentzian, but rather exhibit varying amounts of asymmetry about their respective peaks. We analyze p-mode line asymmetry using both a simplified one-dimensional…

Astrophysics · Physics 2007-05-23 Pawan Kumar , Douglas Abrams

The excitation rate P of solar p-modes is computed with a model of stochatic excitation which involves constraints on the averaged properties of the solar turbulence. These constraints are obtained from a 3D simulation. Resulting values for…

Astrophysics · Physics 2007-05-23 R. Samadi , M. J. Goupil , Y. Lebreton , A. Nordlund , F. Baudin

A review on acoustic mode damping and excitation in solar-type stars is presented. Current models for linear damping rates are discussed in the light of recent low-degree solar linewidth measurements with emphasis on the…

Astrophysics · Physics 2007-05-23 G. Houdek

We model the stochastic excitation of acoustic modes in solar-like pulsators taking into account the action of differential rotation. We derive the theoretical formalism for the stochastic excitation with differential rotation and make use…

Solar and Stellar Astrophysics · Physics 2024-10-31 Gabriel Biscarrat , Leïla Bessila , Stéphane Mathis

The mechanism for excitation of p-modes in rapidly oscillating, peculiar A (roAp, or cool chemically peculiar, CP) stars is unknown. Observations strongly suggest that acoustic modes in roAp stars are causally linked to the stars' magnetic…

Astrophysics · Physics 2007-05-23 E. J. Zita