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Related papers: 2D computations of g modes

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We calculate the second order perturbations driven by oscillation modes of rotating stars. Assuming that the typical amplitude $a$ of oscillation modes is small, we expand the perturbed quantities as $Q=Q^{(0)}+Q^{(1)}+Q^{(2)}+\cdots$ where…

Solar and Stellar Astrophysics · Physics 2025-07-11 Umin Lee

Gravity modes (g modes), mixed gravito-acoustic modes (mixed modes), and gravito-inertial modes (gi modes) possess unmatched properties as probes for stars with radiative interiors. The structural and dynamical constraints that they are…

Despite more and more observational data, stellar acoustic oscillation modes are not well understood as soon as rotation cannot be treated perturbatively. In a way similar to semiclassical theory in quantum physics, we use acoustic ray…

Solar and Stellar Astrophysics · Physics 2011-09-16 M. Pasek , B. Georgeot , F. Lignieres , D. R. Reese

We propose a new method to study the quasi-normal modes of rotating relativistic stars. Oscillations are treated as perturbations in the frequency domain of the stationary, axisymmetric background describing a rotating star. The perturbed…

General Relativity and Quantum Cosmology · Physics 2008-11-26 V. Ferrari , L. Gualtieri , S. Marassi

A numerical method of mode analysis of rapidly rotating relativistic stellar models by the Cowling approximation is applied to rotating neutron stars with realistic equations of state. For selected equations of state, eigenvalues and…

Astrophysics · Physics 2009-10-30 S. Yoshida , Y. Eriguchi

We carry out 3-D numerical simulations of the dynamical instability in rapidly rotating stars initially modeled as polytropes with n = 1.5, 1.0, and 0.5. The calculations are done with a SPH code using Newtonian gravity, and the…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Janet L. Houser , Joan M. Centrella

The standard theory of pulsations deals with the frequencies and growth rates of infinitesimal perturbations in a stellar model. Modes which are calculated to be linearly driven should increase their amplitudes exponentially with time; the…

Solar and Stellar Astrophysics · Physics 2019-02-18 M. H. Montgomery , J. J. Hermes , D. E. Winget

In this study, we perform full three dimensional numerical relativity simulations of non-rotating general relativistic stars. Extending the studies for polytropic equation of state, we investigate the accuracy and robustness of numerical…

General Relativity and Quantum Cosmology · Physics 2023-06-16 Swarnim Shashank , Fatemeh Hossein Nouri , Anshu Gupta

Context: Recent calculations of pulsation modes in rapidly rotating polytropic models and models based on the Self-Consistent Field method (MacGregor et al. 2007) have shown that the frequency spectrum of low degree pulsation modes can be…

Solar and Stellar Astrophysics · Physics 2015-05-13 D. R. Reese , M. J. Thompson , K. B. MacGregor , S. Jackson , A. Skumanich , T. S. Metcalfe

Knowledge of the geometry of pulsational modes is a prerequisite for seismic modelling of stars. In the case of slowly pulsating B-type (SPB) pulsators, the simple zero-rotation approach so far used for mode identification is usually not…

Solar and Stellar Astrophysics · Physics 2015-06-24 W. Szewczuk , J. Daszyńska-Daszkiewicz

The relation of period spacing ($\Delta P$) versus period ($P$) of dipole prograde g modes is known to be useful to measure rotation rates in the g-mode cavity of rapidly rotating $\gamma$ Dor and slowly pulsating B (SPB) stars. In a…

Solar and Stellar Astrophysics · Physics 2021-03-03 Hideyuki Saio , Masao Takata , Umin Lee , Gang Li , Timothy Van Reeth

The axial mode oscillations are examined for relativistic rotating stars with uniform angular velocity. Using the slow rotation formalism and the Cowling approximation, we have derived the equations governing the r-mode oscillations up to…

Astrophysics · Physics 2015-06-24 Yasufumi Kojima , Masayasu Hosonuma

Almost none of the r-modes ordinarily found in rotating stars exist, if the star and its perturbations obey the same one-parameter equation of state; and rotating relativistic stars with one-parameter equations of state have no pure r-modes…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Keith H. Lockitch , John L. Friedman

Rotation is expected to have an important influence on the structure and the evolution of stars. However, the mechanisms of angular momentum transport in stars remain theoretically uncertain and very complex to take into account in stellar…

Context. Thanks to the high-precision photometry from space missions such as Kepler and TESS, tidal perturbations and tilting of pulsations have been detected in more than a dozen binary systems. However, only two of these were g-mode…

Solar and Stellar Astrophysics · Physics 2023-03-15 T. Van Reeth , C. Johnston , J. Southworth , J. Fuller , D. M. Bowman , L. Poniatowski , J. Van Beeck

Interpreting the oscillations of massive and intermediate mass stars remains a challenging task. In fast rotators, the oscillation spectrum of p-modes is a superposition of sub-spectra which correspond to different types of modes, among…

Solar and Stellar Astrophysics · Physics 2019-11-26 Benjamin Evano , François Lignières , Bertrand Georgeot

Asteroseismology with the space-borne missions CoRoT and Kepler provides a powerful mean of testing the modeling of transport processes in stars. Rotational splittings are currently measured for a large number of red giant stars and can…

Solar and Stellar Astrophysics · Physics 2015-06-12 M. J. Goupil , B. Mosser , J. P. Marques , R. M. Ouazzani , K. Belkacem , Y. Lebreton , R. Samadi

We use perturbation theory and the relativistic Cowling approximation to numerically compute characteristic oscillation modes of rapidly rotating relativistic stars which consist of a perfect fluid obeying a polytropic equation of state. We…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Stratos Boutloukos , Hans-Peter Nollert

The space missions CoRoT and Kepler provide high quality data that allow us to test the transport of angular momentum in stars by the seismic determination of the internal rotation profile. Our aim is to test the validity of the seismic…

Solar and Stellar Astrophysics · Physics 2015-06-15 R-M. Ouazzani , M. J. Goupil , M-A. Dupret , J. P. Marques

We present an asymptotic theory that describes regular frequency spacings of pressure modes in rapidly rotating stars. We use an asymptotic method based on an approximate solution of the pressure wave equation constructed from a stable…

Solar and Stellar Astrophysics · Physics 2012-09-27 Michael Pasek , François Lignières , Bertrand Georgeot , Daniel R. Reese