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Related papers: Pulsation models for the roAp star HD 134214

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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

We calculate axisymmetric toroidal modes of magnetized neutron stars with a solid crust. We assume the interior of the star is threaded by a poloidal magnetic field that is continuous at the surface with the outside dipole field whose…

Astrophysics · Physics 2009-11-13 U. Lee

We present a total of 57 days of contiguous, high-cadence photometry (14 days in 2004 and 43 in 2005) of the star BD+18 4914 obtained with the MOST satellite. We detect 16 frequencies down to a signal-to-noise of 3.6 (amplitude \~ 0.5…

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

We present improvement and confirmation of identified frequencies and pulsation modes for the $\gamma$ Doradus star HD 189631. This work improves upon previous studies by incorporating a significant number of additional spectra and precise…

Solar and Stellar Astrophysics · Physics 2015-06-22 Matthew W. Davie , Karen R. Pollard , Peter L. Cottrell , Emily Brunsden , Duncan J. Wright , Peter De Cat

Among the early B-type stars, He-rich Bp stars exhibit the strongest large-scale organized magnetic fields with a predominant dipole contribution. The presence of $\beta$ Cep-like pulsations in the typical magnetic early Bp-type star HD…

Solar and Stellar Astrophysics · Physics 2016-10-13 S. P. Järvinen , S. Hubrig , I. Ilyin , M. Schöller , M. Briquet

Low-mass ($M_{\star}/M_{\sun} \lesssim 0.45$) white dwarfs, including the so called extremely low-mass white dwarfs (ELM, $M_{\star}/M_{\sun } \lesssim 0.18-0.20$), are being currently discovered in the field of our Galaxy through dedicated…

Solar and Stellar Astrophysics · Physics 2015-12-09 Alejandro H. Córsico , Leandro G. Althaus

A new two dimensional non-perturbative code to compute accurate oscillation modes of rapidly rotating stars is presented. The 2D calculations fully take into account the centrifugal distorsion of the star while the non perturbative method…

Solar and Stellar Astrophysics · Physics 2013-01-14 R-M. Ouazzani , I. W. Roxburgh , M-A Dupret

EC14012-1446 was observed by Handler et al. in April 2004, June 2004, May 2005, and April 2007, and by Provencal et al. in 2008. We review the observations together and obtain 34 independent frequencies. According to the frequency splitting…

Solar and Stellar Astrophysics · Physics 2015-06-22 Yanhui Chen , Yan Li

New non-linear hydrodynamic models have been constructed to simulate the radial pulsations observed in the extreme helium star V652 Her. These use a finer zoning to allow higher radial resolution than in previous simulations. Models…

Solar and Stellar Astrophysics · Physics 2021-10-13 C. Simon Jeffery , Pilar Montañés-Rodríguez , Hideyuki Saio

We performed 2D and full 3D magnetohydrodynamic simulations of disk accretion to a rotating star with an aligned or misaligned dipole magnetic field. We investigated the rotational equilibrium state and derived from simulations the ratio…

Using MOST (Microvariability and Oscillations of STars) satellite guide star photometry, we have discovered a metallic A star showing hybrid p- and g-mode pulsations. HD 114839 was observed nearly continuously for 10 days in March, 2005. We…

Using linear non-adabatic pulsation analysis, we explore the radial-mode (p-mode) stability of stars across a wide range of mass (0.2 <= M <= 50 Msun), composition (0 <= X <= 0.7, Z=0.001, 0.02), effective temperature (3 000 <= T_eff <= 40…

Solar and Stellar Astrophysics · Physics 2016-03-09 C. S. Jeffery , H. Saio

The DAV star, HS0507+0434B, was observed by Fu et al. (2013) in 2007 and from 2009 December to 2010 January. There were a total of six triplets with nearly equal split, which were identified as $l$ = 1 modes caused by rotation. In order to…

Solar and Stellar Astrophysics · Physics 2016-04-12 YanHui Chen , Yan Li

We investigate non-axisymmetric low frequency modes of a rotating and magnetized neutron star, assuming that the star is threaded by a dipole magnetic field whose strength at the stellar surface, $B_0$, is less than $\sim 10^{12}$G, and…

Solar and Stellar Astrophysics · Physics 2015-05-14 Umin Lee

In this paper, we improve the previous work on the MHD Alfven wave oscillation model for the neutron star (NS) kHz quasi-periodic oscillations (QPOs), and compare the model with the updated twin kHz QPO data. For the 17 NS X-ray sources…

Astrophysics · Physics 2008-11-26 C. M. Zhang , H. X. Yin , Y. H. Zhao , H. K. Chang , L. M. Song

Results of mode identification and seismic modelling of the $\beta$ Cep/SBP star 12 Lacertae are presented. Using data on the multi-colour photometry and radial velocity variations, we determine or constrain the mode degree, $\ell$, for all…

Solar and Stellar Astrophysics · Physics 2013-04-16 J. Daszyńska-Daszkiewicz , W. Szewczuk , P. Walczak

Excitation of radial oscillations in population I (X=0.7, Z=0.02) red supergiants is investigated using the solution of the equations of radiation hydrodynamics and turbulent convection. The core helium burning stars with masses 8M_odot <=…

Solar and Stellar Astrophysics · Physics 2015-06-03 Yuri A. Fadeyev

Context: New observational means such as the space missions CoRoT and Kepler and ground-based networks are and will be collecting stellar pulsation data with unprecedented accuracy. A significant fraction of the stars in which pulsations…

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

TIC033834484 and TIC309658435 are long-period pulsating subdwarf B star, which were observed extensively (675 and 621 days, respectively) by the Transiting Exoplanet Survey Satellite (TESS). The high-precision photometric light curve…

Solar and Stellar Astrophysics · Physics 2022-12-07 Murat Uzundag , Roberto Silvotti , Andrzej S. Baran , Maja Vuckovic , Péter Nemeth , Sumanta K. Sahoo , Mike Reed