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Related papers: Be Stars: Rapidly Rotating Pulsators

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Over the last decade, large-scale, organized (generally dipolar) magnetic fields with a strength between 0.1 and 20 kG were detected in dozens of OB stars. This contribution reviews the impact of such magnetic fields on the stellar winds of…

Solar and Stellar Astrophysics · Physics 2015-06-12 Yael Naze

Rapid rotation is a fundamental characteristic of classical Be stars and a crucial property allowing for the formation of their circumstellar disks. Past evolution in a mass and angular momentum transferring binary system offers a plausible…

We present here the results of our research for B-type pulsators in low metallicity environments, searching for short-term periodic variability in a large sample of B and Be stars in the Magellanic Clouds (MC), for which the fundamental…

Solar and Stellar Astrophysics · Physics 2009-02-26 P. D. Diago , J. Gutiérrez-Soto , J. Fabregat , C. Martayan

Here we determine the projected rotational velocity of 10 Be stars using Fourier Transform Method. Also, we discuss the gravity darkening and extend of deviation from solid body rotation for our sample of stars. We found that 7 of…

Astrophysics · Physics 2007-05-23 Natasa Gavrilovic

We model a rotating star as a compressible fluid subject to gravitational forces. In almost all the mathematical literature the entropy is considered to be constant. Here we allow it to be variable. We consider a star that steadily rotates…

Analysis of PDEs · Mathematics 2022-04-19 Juhi Jang , Walter A. Strauss , Yilun Wu

The eigen frequencies of radial pulsations of neutron stars are calculated in a strong magnetic field. At low densities we use the magnetic BPS equation of state(EOS) similar to that obtained by Lai and Shapiro while at high densities the…

Astrophysics · Physics 2009-11-06 V. K. Gupta , Vinita Tuli , S. Singh , J. D. Anand , Ashok Goyal

A rotating star may be modeled as a continuous system of particles attracted to each other by gravity and with a given total mass and prescribed angular velocity. Mathematically this leads to the Euler-Poisson system. We prove an existence…

Analysis of PDEs · Mathematics 2018-04-17 Yilun Wu , Walter Strauss

We speculate that stationary force-free pulsar magnetospheres are screw unstable, and the spin-down power of real pulsars is carried by turbulent Poynting jets. The turbulent jet entrains poloidal flux as it propagates away from the star.…

Astrophysics · Physics 2007-05-23 Andrei Gruzinov

Magnetic confinement of stellar winds leads to the formation of magnetospheres, which can be sculpted into Centrifugal Magnetospheres (CMs) by rotational support of the corotating plasma. The conditions required for the CMs of magnetic…

We have obtained 40 high-resolution circular spectropolarimetric measurements of 12 slowly-pulsating B (SPB) stars, 8 Beta Cephei stars and two Be stars with the ESPaDOnS and NARVAL spectropolarimeters. The aim of these observations is to…

Solar and Stellar Astrophysics · Physics 2015-05-13 J. Silvester , C. Neiner , H. F. Henrichs , G. A. Wade , V. Petit , E. Alecian , A. -L. Huat , C. Martayan , J. Power , O. Thizy

Boson stars are self-gravitating solutions made entirely of fundamental massive bosonic fields. Here we investigate mini boson stars in $D$ non-compact spacetime dimensions and we show that they are dynamically unstable for $D>4$.

General Relativity and Quantum Cosmology · Physics 2024-09-18 Edgardo Franzin

The gravitational radiation emitted by a rotating magnetic dipole is calculated. Formulas for the polarization amplitudes and the radiated power are obtained in closed forms. A comparison is made with other sources of gravitational and…

General Relativity and Quantum Cosmology · Physics 2017-01-16 Shahen Hacyan

The origin of the magnetic fields of the chemically peculiar main sequence Ap/Bp stars is still matter of intense debate. The recent discoveries of magnetic fields in Herbig Ae/Be stars using high resolution data obtained with the…

Rapidly rotating Be stars are observed as shell stars when the decretion disc is viewed edge on. Transitions between the two implies that the discs may be warped and precessing. Type II X-ray outbursts are thought to occur when the warped…

Solar and Stellar Astrophysics · Physics 2015-05-28 Rebecca G. Martin , J. E. Pringle , Christopher A. Tout , Stephen H. Lubow

We consider the electrodynamics of in-spiraling binary pulsars, showing that there are two distinct ways in which they may emit radiation. On the one hand, even if the pulsars do not rotate, we show that in vacuo orbital rotation generates…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Emanuele Sobacchi , Mario Vietri

Stellar pulsations in rotating relativistic stars are reviewed. Slow rotation approximation is applied to solving the Einstein equations. The rotational effects on the non-axisymmetric oscillations are explicitly shown in the polar and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yasufumi Kojima

We review the current state of knowledge of magnetic fields inside stars, concentrating on recent developments concerning magnetic fields in stably stratified (zones of) stars, leaving out convective dynamo theories and observations of…

Solar and Stellar Astrophysics · Physics 2017-04-11 J. Braithwaite , H. C. Spruit

We study the bending of jets in binary stellar systems. A compact companion accretes mass from the slow wind of the mass-losing primary star, forms an accretion disk, and blows two opposite jets. These fast jets are bent by the slow wind.…

Astrophysics · Physics 2009-11-11 Noam Soker , Gili Bisker

Photospheric nitrogen abundances for a sample of 26 Be stars and 16 normal B stars were found using high-resolution spectra from the Magnetism in Massive Stars (MiMeS) spectroscopic survey. Nitrogen abundances were obtained using non-LTE…

Solar and Stellar Astrophysics · Physics 2017-08-23 A. Ahmed , T. A. A. Sigut

We present multiple epochs of H-alpha spectroscopy for 47 members of the open cluster NGC 3766 to investigate the long term variability of its Be stars. Sixteen of the stars in this sample are Be stars, including one new discovery. Of…