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Related papers: Alfv\'en Polar Oscillations of Relativistic Stars

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Recent observations with the Hinode Solar Optical Telescope display an active region prominence whose fine threads oscillate in the vertical direction as they move along a path parallel to the photosphere. A seismological analysis of this…

Astrophysics · Physics 2009-11-13 J. Terradas , I. Arregui , R. Oliver , J. L. Ballester

We present an one-dimensional numerical study of Alfven waves propagating along a radial magnetic field. Neglecting losses, any spherical Alfven wave, no matter how small its initial amplitude is, becomes nonlinear at sufficiently large…

Astrophysics · Physics 2009-10-30 Ulf Torkelsson , G. Christopher Boynton

We investigate the electromagnetic interaction of a relativistic stellar wind with a planet or a smaller body in orbit around the star. This may be relevant to objects orbiting a pulsar, such as PSR B1257+12 and PSR B1620-26 that are…

Earth and Planetary Astrophysics · Physics 2015-05-28 Fabrice Mottez , J. Heyvaerts

In-situ observations in the Earth's and Saturn's magnetosheaths and in the solar wind reveal the presence of Alfv\'en vortices as intermittent structures in the range of scales from fluid lengths down to few ion lengths. The density and the…

Plasma Physics · Physics 2020-04-16 Dusan Jovanovic , Olga Alexandrova , Milan Maksimovic , Milivoj Belic

Context. The influence of magnetic fields on stellar evolution remains unresolved. It has been proposed that if there is a large-scale magnetic field in the stellar interior, torsional waves could arise, efficiently transporting angular…

Solar and Stellar Astrophysics · Physics 2025-04-09 Koh Takahashi , Norbert Langer

Stars are, generically, rotating and magnetised objects with a misalignment between their magnetic and rotation axes. Since a magnetic field induces a permanent distortion to its host, it provides effective rigidity even to a fluid star,…

Solar and Stellar Astrophysics · Physics 2017-03-23 S. K. Lander , D. I. Jones

Neutron stars can harbor extremely strong magnetic fields, yet the structure and stability of their magnetic field configuration remain poorly understood. Observations of pulsars indicate that the large-scale external field is predominantly…

High Energy Astrophysical Phenomena · Physics 2026-05-25 Aurora Capobianco , William Cook , Sebastiano Bernuzzi , Brynmor Haskell , Jacob Fields

We present 3D MHD simulations of purely toroidal and mixed poloidal-toroidal magnetic field configurations to study the behavior of the Tayler instability. For the first time the simultaneous action of rotation and magnetic diffusion are…

Solar and Stellar Astrophysics · Physics 2015-05-27 Juan C. Ibañez-Mejia , Jonathan Braithwaite

Alfv\'{e}nic component of MHD turbulence damps Alfv\'{e}nic waves. The consequences of this effect are important for many processes, from cosmic ray (CR) propagation to launching outflows and winds in galaxies and other magnetized systems.…

Astrophysics of Galaxies · Physics 2022-01-17 Alex Lazarian , Siyao Xu

Most astrophysical fluids are turbulent and magnetized. Fluctuations of polarization provide a promising way to study astrophysical magnetic turbulence. We discuss polarization that arises from grains and atoms aligned in respect to…

Astrophysics · Physics 2009-11-11 A. Lazarian , Huirong Yan

We initiate numerical studies of differentially rotating magnetised (proto) neutron stars by studying - through construction from first principles - the coupling between an assumed differential rotation and an impressed magnetic field. For…

Astrophysics · Physics 2007-05-23 A. V. Thampan

We derive the perturbation equations for relativistic stars in scalar-tensor theories of gravity and study the corresponding oscillation spectrum. We show that the frequency of the emitted gravitational waves is shifted proportionally to…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Hajime Sotani , Kostas D. Kokkotas

Alfv\'en waves are primal and pervasive in space plasmas and significantly contributes to microscale fluctuations in the solar wind and some heliospheric processes. Here, we demonstrate the first observable distinct feature of Alfv\'en wave…

Space Physics · Physics 2018-10-16 Anil N. Raghav , Ankita Kule

The propagation of linear Alfv\'en wave pulses in an inhomogeneous plasma near a 2D coronal null point is investigated. When a uniform plasma density is considered, it is seen that an initially planar Alfv\'en wavefront remains planar,…

Solar and Stellar Astrophysics · Physics 2014-07-08 J. A. McLaughlin

We study non-linear axisymmetric pulsations of rotating relativistic stars using a general relativistic hydrodynamics code under the assumption of a conformal flatness. We compare our results to previous simulations where the spacetime…

Astrophysics · Physics 2009-11-11 Harald Dimmelmeier , Nikolaos Stergioulas , Jose A. Font

Self-gravitating stellar disks with random motion support both exponentially growing and, in some cases, purely oscillatory axisymmetric bending modes, unlike their cold disk counterparts. A razor-thin disk with even a very small degree of…

Astrophysics · Physics 2009-10-28 J A Sellwood

We study the effect of poloidal magnetic field on type I planetary migration by linear perturbation analysis in the shearing-sheet approximation and the analytic results are compared with numerical calculations. In contrast to the…

Astrophysics · Physics 2009-11-13 Takayuki Muto , Masahiro N. Machida , Shu-ichiro Inutsuka

We study the magnetosphere of a slowly rotating magnetized neutron star subject to toroidal oscillations in the relativistic regime. Under the assumption of a zero inclination angle between the magnetic moment and the angular momentum of…

High Energy Astrophysical Phenomena · Physics 2015-05-18 V. S. Morozova , B. J. Ahmedov , O. Zanotti

In recent years, astronomers have witnessed major progresses in the field of stellar physics. This was made possible thanks to the combination of a solid theoretical understanding of the phenomena of stellar pulsations and the availability…

Solar and Stellar Astrophysics · Physics 2017-11-29 Margarida S. Cunha

When a differentially rotating magnetic star undergoes ``turn-over'', i.e., its magnetic symmetry axis is inclining at a gradually increasing angle with respect to its invariant angular momentum axis up to the perpendicular position…

Astrophysics · Physics 2007-05-23 V. S. Geroyannis , P. J. Papasotiriou , I. Valiaka