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Related papers: Modelling the excitation of acoustic modes in Alph…

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Inertial modes have been observed on the Sun at low longitudinal wavenumbers. These modes probe the dynamics and structure of the solar convection zone down to the tachocline. While linear analysis allows the complex eigenfrequencies and…

Solar and Stellar Astrophysics · Physics 2023-05-31 J. Philidet , L. Gizon

The $\alpha$ Cen stellar system is the closest neighbour to our Sun. Its main component is a binary composed of two main-sequence stars, one more massive than the Sun and one less massive. The system's bright magnitude led to a wealth of…

Solar and Stellar Astrophysics · Physics 2021-02-10 Sébastien Salmon , Valérie Van Grootel , Gaël Buldgen , Marc-Antoine Dupret , Patrick Eggenberger

The discovery of solar-like oscillations in the giant star xy Hya (G7III) was reported by Frandsen et al. (2002). Their frequency analysis was very limited due to alias problems in the data set (caused by single-site observations). The…

Astrophysics · Physics 2009-11-10 D. Stello , H. Kjeldsen , T. R. Bedding , J. De Ridder , C. Aerts , F. Carrier , S. Frandsen , .

Recent observations and theoretical studies support the theory that solar-type oscillations are intrinsically stable but excited stochastically by the turbulent convection in the outer layers of the star. The acoustic noise generated by the…

Astrophysics · Physics 2007-05-23 Reza Samadi , Guenter Houdek

HD 187547 was the first candidate that led to the suggestion that solar-like oscillations are present in delta Scuti stars. Longer observations, however, show that the modes interpreted as solar-like oscillations have either very long mode…

Solar and Stellar Astrophysics · Physics 2015-06-23 V. Antoci , M. Cunha , G. Houdek , H. Kjeldsen , R. Trampedach , G. Handler , T. Lueftinger , T. Arentoft , S. Murphy

Delta Scuti (delta Sct) stars are opacity-driven pulsators with masses of 1.5-2.5M$_{\odot}$, their pulsations resulting from the varying ionization of helium. In less massive stars such as the Sun, convection transports mass and energy…

Detection of solar gravity modes remains a major challenge to our understanding of the innerparts of the Sun. Their frequencies would enable the derivation of constraints on the core physical properties while their amplitudes can put severe…

Astrophysics · Physics 2009-11-13 K. Belkacem , R. Samadi , M. J. Goupil , M. A. Dupret , A. S. Brun , F. Baudin

Magnetic cycles of solar-like stars influence their internal physics. Thus, the frequency, amplitude, excitation rate, and damping of the acoustic oscillation modes (p-modes) vary with the cycle over time. We need to understand the impact…

Solar and Stellar Astrophysics · Physics 2024-11-08 E. Panetier , S. N. Breton , R. A. García , A. Jiménez , T. Foglizzo

Forward asteroseismic modelling plays an important role towards a complete understanding of the physics taking place in deep stellar interiors. With a dynamical mass in the range over which models develop convective cores while in the main…

Solar and Stellar Astrophysics · Physics 2019-04-25 Benard Nsamba , Tiago L. Campante , Mário J. P. F. G. Monteiro , Margarida S. Cunha , Sérgio G. Sousa

We use hydrodynamical simulations of galaxy clusters and groups to study the effect of pre-heating on the entropy structure of the ICM. Our simulations account for non-gravitational heating of the gas either by imposing a minimum entropy…

Astrophysics · Physics 2009-11-11 S. Borgani , A. Finoguenov , S. T. Kay , T. J. Ponman , V. Springel , P. Tozzi , G. M. Voit

Stochatic excitation of stellar oscillations by turbulent convection is investigated and an expression for the power injected into the oscillations by the turbulent convection of the outer layers is derived which takes into account…

Astrophysics · Physics 2009-11-06 Reza Samadi , Marie-Jo Goupil

In this paper, we aim to develop a predictive model for solar radial $p$-mode line profiles in the velocity spectrum. Unlike the approach favoured by prior studies, this model is not described by free parameters and we do not use fitting…

Solar and Stellar Astrophysics · Physics 2020-03-18 J. Philidet , K. Belkacem , R. Samadi , C. Barban , H. -G. Ludwig

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

In this paper we compare fully compressible (Meakin & Arnett 2006a,b) and anelastic (Kuhlen, Woosley, & Glatzmaier 2003) simulations of stellar oxygen shell burning. It is found that the two models are in agreement in terms of the velocity…

Astrophysics · Physics 2011-02-11 Casey A. Meakin , David Arnett

We derive knowledge on the global and structural parameters of low-mass stars using asteroseismology and taking advantage of the stellar collective behavior within open clusters. We build stellar models and compute the seismic signal…

Astrophysics · Physics 2008-11-26 L. Piau , J. Ballot , S. Turck-Chieze

Several types of inertial modes have been detected on the Sun. Properties of these inertial modes have been studied in the linear regime but have not been studied in nonlinear simulations of solar rotating convection. Comparing the…

Solar and Stellar Astrophysics · Physics 2022-10-19 Yuto Bekki , Robert H. Cameron , Laurent Gizon

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 excitation mechanism of low degree acoustic modes is investigated through the analysis of the stochastic time variations of their energy. The correlation between the energies of two different modes is interpreted as the signature of the…

Astrophysics · Physics 2007-05-23 Thierry Foglizzo

We report the most sensitive search yet made for solar-like oscillations. We observed the star alpha Cen A in Balmer-line equivalent widths over six nights with both the 3.9m Anglo-Australian Telescope and the ESO 3.6m telescope. We set an…

Astrophysics · Physics 2009-10-31 H. Kjeldsen , T. R. Bedding , S. Frandsen , T. H. Dall

Recent photometric observations of massive stars have identified a low-frequency power excess which appears as stochastic low-frequency variability in light curve observations. We present the oscillation properties of high resolution…

Solar and Stellar Astrophysics · Physics 2024-05-01 William Thompson , Falk Herwig , Paul R. Woodward , Huaqing Mao , Pavel Denissenkov , Dominic M. Bowman , Simon Blouin