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Related papers: Oscillations of 2D ESTER models. I. The adiabatic …

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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

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

According to a recent ray-based asymptotic theory, the high-frequency p-mode spectrum of rapidly rotating stars is a superposition of frequency subsets associated with dynamically independent regions of the ray-dynamics phase space. At high…

Solar and Stellar Astrophysics · Physics 2015-05-20 F. Lignieres , B. Georgeot , J. Ballot

Asymmetries in the observed rotational splittings of a multiplet contain information about the star's rotation profile and internal magnetic field. However, to exploit this information, highly accurate theoretical predictions are needed. We…

Solar and Stellar Astrophysics · Physics 2025-11-14 J. S. G. Mombarg , V. Vanlaer , S. B. Das , M. Rieutord , C. Aerts , L. Bugnet , S. Mathis , D. R. Reese , J. Ballot

Asteroseismology is a powerful tool for probing the internal structures of stars by using their natural pulsation frequencies. It relies on identifying sequences of pulsation modes that can be compared with theoretical models, which has…

We revisit the problem of radial pulsations of neutron stars by computing four general-relativistic polytropic models, in which "density" and "adiabatic index" are involved with their discrete meanings: (i) "rest-mass density" or (ii)…

General Relativity and Quantum Cosmology · Physics 2014-06-17 Vassilis Geroyannis , Georgios Kleftogiannis

Oscillation frequencies are the most accurate properties one can measure for a star, potentially allowing detailed tests of stellar models and evolution theories. We briefly review asteroseismology for two classes of stars. In delta Scuti…

Astrophysics · Physics 2007-05-23 Hans Kjeldsen , Timothy R. Bedding

We present the results of modelling the subgiant star $\beta$ Hydri using the seismic observational constraints. We have computed several grids of stellar evolutionary tracks using Aarhus STellar Evolution Code (ASTEC,…

Solar and Stellar Astrophysics · Physics 2011-03-28 G. Doğan , I. M. Brandão , T. R. Bedding , J. Christensen-Dalsgaard , M. S. Cunha , H. Kjeldsen

Using weakly non-linear theory of oscillation, we estimate the amplitudes of low frequency modes in a slowly pulsating B (SPB) star, taking account of the effects of rotation on the modes. Applying the formulation by Schenk et al (2002), we…

Solar and Stellar Astrophysics · Physics 2015-06-03 Umin Lee

The understanding of the rotational evolution of early-type stars is deeply related to that of anisotropic mass and angular momentum loss. In this paper, we aim to clarify the rotational evolution of rapidly rotating early-type stars along…

Solar and Stellar Astrophysics · Physics 2019-05-22 D. Gagnier , M. Rieutord , C. Charbonnel , B. Putigny , F. Espinosa Lara

TESS observations of pulsating hot main sequence stars paint a very different picture from what is currently accepted. There are large numbers of delta Scuti (DSCT) stars hotter than the theoretical hot edge of the instability strip,…

Solar and Stellar Astrophysics · Physics 2024-01-25 Luis A. Balona

Asteroseismology has opened a window on the internal physics of thousands of stars, by relating oscillation spectra properties to the internal physics of stars. Mode identification, namely the process of associating a measured oscillation…

Solar and Stellar Astrophysics · Physics 2022-09-21 Giovanni Marcello Mirouh

Context: With the launch of space missions devoted to asteroseismology (like COROT), the scientific community will soon have accurate measurements of pulsation frequencies in many rapidly rotating stars. Aims: The present work focuses on…

Astrophysics · Physics 2008-11-26 D. Reese , F. Lignières , M. Rieutord

In this talk I present the latest results of the ESTER project that has taken up the challenge of building two dimensional (axisymmetric) models of stars rotating at any rotation rate. In particular, I focus on main sequence massive and…

Solar and Stellar Astrophysics · Physics 2015-09-30 Michel Rieutord

The gravito-inertial waves propagating over a shellular baroclinic flow inside a rotating spherical shell are analysed using the Boussinesq approximation. The wave properties are examined by computing paths of characteristics in the…

Solar and Stellar Astrophysics · Physics 2016-08-24 Giovanni M. Mirouh , Clément Baruteau , Michel Rieutord , Jérôme Ballot

As an extension of our previous work, we investigate the dynamical instability against nonaxisymmetric bar-mode deformations of differentially rotating stars in Newtonian gravity varying the equations of state and velocity profiles. We…

Astrophysics · Physics 2009-11-07 Masaru Shibata , Shigeyuki Karino , Yoshiharu Eriguchi

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

We present an asteroseismic study of the fast rotating star HD187642 (Altair), recently discovered to be a delta Scuti pulsator. We have computed models taking into account rotation for increasing rotational velocities. We investigate the…

Astrophysics · Physics 2009-11-10 J. C. Suarez , H. Bruntt , D. Buzasi

Hybrid $\delta$ Scuti-$\gamma$ Doradus pulsating stars show acoustic ($p$) oscillation modes typical of $\delta$ Scuti variable stars, and gravity ($g$) pulsation modes characteristic of $\gamma$ Doradus variable stars simultaneously…

Solar and Stellar Astrophysics · Physics 2016-12-28 J. P. Sánchez Arias , A. H. Córsico , L. G. Althaus

A comparison between linear stability analysis and observations of pulsation modes in five delta Scuti stars, belonging to the same cluster, is presented. The study is based on the work by Michel et al. (1999), in which such a comparison…

Astrophysics · Physics 2009-06-23 J. C. Suarez , E. Michel , G. Houdek , F. Perez Hernandez , Y. Lebreton