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Related papers: Porto Oscillation Code (POSC)

200 papers

The equations describing nonradial adiabatic oscillations of differentially rotating relativistic stars are derived in relativistic slow rotation approximation. The differentially rotating configuration is described by a perturbative…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Adamantios Stavridis , Andrea Passamonti , Kostas Kokkotas

Sun-like stellar oscillations are excited by turbulent convection and have been discovered in some 500 main sequence and sub-giant stars and in more than 12,000 red giant stars. When such stars are near gravitational wave sources, low-order…

Solar and Stellar Astrophysics · Physics 2015-07-14 Ilídio Lopes , Joseph Silk

We consider a strongly heterogeneous medium saturated by an incompressible viscous fluid as it appears in geomechanical modeling. This poroelasticity problem suffers from rapidly oscillating material parameters, which calls for a thorough…

Numerical Analysis · Mathematics 2018-12-27 Robert Altmann , Eric Chung , Roland Maier , Daniel Peterseim , Sai-Mang Pun

It has been established earlier that sharp features like the base of the convective zone or the second helium ionisation zone inside a star give rise to sinusoidal oscillations in the frequencies of pulsation. The acoustic depth of such…

Solar and Stellar Astrophysics · Physics 2010-04-19 Anwesh Mazumdar , Eric Michel

Recent observations of rapidly rotating stars have revealed the presence of regular patterns in their pulsation spectra. This has raised the question as to their physical origin, and in particular, whether they can be explained by an…

Solar and Stellar Astrophysics · Physics 2015-06-17 Daniel R. Reese , Francisco Espinosa Lara , Michel Rieutord

We solve the dynamical GR equations for the spherically symmetric evolution of compact stars in the vicinity of the maximum mass, for which instability sets in according to linear perturbation theory. The calculations are done with the…

General Relativity and Quantum Cosmology · Physics 2015-08-06 Alessandro Brillante , Igor Mishustin

A new simulation technique to obtain the synchronized steady-state solutions existing in coupled oscillator systems is presented. The technique departs from a semi-analytical formulation presented in previous works. It extends the model of…

Systems and Control · Electrical Eng. & Systems 2024-04-22 Pedro Umpierrez , Victor Arana , Sergio Sancho

We review the derivation of the pulsations equations for spherically symmetric boson stars and then make a thorough study of the radial oscillation frequencies for the fundamental and first excited modes. We do this for self-interacting…

General Relativity and Quantum Cosmology · Physics 2021-06-16 Ben Kain

Linear damping rates and modal frequency corrections of radial oscillation modes in selected LEGACY main-sequence stars are estimated by means of a nonadiabatic stability analysis. The selected stellar sample covers stars observed by Kepler…

Solar and Stellar Astrophysics · Physics 2019-05-08 G. Houdek , M. N. Lund , R. Trampedach , J. Christensen-Dalsgaard , R. Handberg , T. Appourchaux

Pulsars are unique astrophysical laboratories because of their clock-like timing precision, providing new ways to test general relativity and detect gravitational waves. One impediment to high-precision pulsar timing experiments is timing…

Solar and Stellar Astrophysics · Physics 2015-05-20 Rachel Rosen , Maura A. McLaughlin , Susan E. Thompson

With the rapid development of asteroseismology thanks to space-based photometry missions such as CoRoT, Kepler, TESS, and in the future, PLATO, and the use of inversion techniques, quasi-model-independent constraints on the stellar…

Solar and Stellar Astrophysics · Physics 2022-07-20 J. Bétrisey , G. Buldgen

The acoustic power injected by turbulent convection into solar-like oscillations depends on the details of the turbulent spectrum. A theoretical formulation for the oscillation power is developed which generalizes previous ones. The…

Astrophysics · Physics 2007-05-23 Reza Samadi , Marie-Jo Goupil , Yveline Lebreton , Annie Baglin

When intermediate mass stars reach their last stages of evolution they show pronounced oscillations. This phenomenon happens when these stars reach the so-called Asymptotic Giant Branch (AGB), which is a region of the Hertzsprung-Russell…

Astrophysics · Physics 2009-11-07 Andreea Munteanu , Enrique Garcia-Berro , Jordi Jose , Emilia Petrisor

Current stellar model predictions of adiabatic oscillation frequencies differ significantly from the corresponding observed frequencies due to the non-adiabatic and poorly understood near-surface layers of stars. However, certain…

Solar and Stellar Astrophysics · Physics 2022-07-20 Kuldeep Verma , Jakob L. Rørsted , Aldo M. Serenelli , Víctor Aguirre Børsen-Koch , Mark L. Winther , Amalie Stokholm

Light curves of oscillating stars provide valuable insights into the stellar interiors. When oscillations from a pair of stars are captured within a single photometric aperture, they can be considered as potential asteroseismic binaries…

Solar and Stellar Astrophysics · Physics 2026-04-28 Jeong Yun Choi , Francisca Espinoza-Rojas , Saskia Hekker

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

In this paper we investigate theoretical pulsation models for the delta Scuti star 44 Tau. The star was monitored during several multisite campaigns which confirmed the presence of radial and nonradial oscillations. Moreover, its…

Astrophysics · Physics 2009-11-13 P. Lenz , A. A. Pamyatnykh , M. Breger , V. Antoci

A new approach to building explicit time-marching stencil computation schemes for the transient 2D acoustic wave equation is implemented. It is based on using Poisson's formula and its three time level modification combined with polynomial…

Numerical Analysis · Mathematics 2019-06-19 Naum M. Khutoryansky

We have calculated the pulsations of massive stars using a nonlinear hydrodynamic code including time-dependent convection. The basic structure models are based on a standard grid published by Meynet et al. (1994). Using the basic…

Solar and Stellar Astrophysics · Physics 2015-06-22 C. C. Lovekin , J. A. Guzik

This paper introduces a spectral Monte Carlo iterative method (SMC) for solving linear Poisson and parabolic equations driven by $\alpha$-stable L\'evy process with $\alpha\in (0,2)$, which was initially proposed and developed by Gobet and…

Numerical Analysis · Mathematics 2025-02-24 Jiaying Feng , Changtao Sheng , Chenglong Xu