English
Related papers

Related papers: Overstable Convective Modes in Rotating Early Type…

200 papers

We discuss non-linear excitation and amplitude saturation of $g$-modes, $r$-modes and overstable convective (OsC) modes in early type main sequence stars, taking account of the effects of three-mode couplings on amplitude evolutions. OsC…

Solar and Stellar Astrophysics · Physics 2022-06-01 Umin Lee

We calculate the second order perturbations driven by oscillation modes of rotating stars. Assuming that the typical amplitude $a$ of oscillation modes is small, we expand the perturbed quantities as $Q=Q^{(0)}+Q^{(1)}+Q^{(2)}+\cdots$ where…

Solar and Stellar Astrophysics · Physics 2025-07-11 Umin Lee

We discuss low-frequency g modes excited by resonant couplings with weakly unstable oscillatory convective modes in the rotating convective core in early-type main-sequence stars. Our non-adiabatic pulsation analyses including the effect of…

Solar and Stellar Astrophysics · Physics 2020-08-12 Umin Lee , Hideyuki Saio

We calculate overstable convective modes of uniformly rotating hot Jupiters, which have a convective core and a thin radiative envelope. Convective modes in rotating planets have complex frequency $\omega$ and are stabilized by rapid…

Earth and Planetary Astrophysics · Physics 2019-02-20 Umin Lee

We study the $r$-modes propagating in steadily mass accreting, nuclear burning, and geometrically thin envelopes on the surface of rotating neutron stars. For the modal analysis, we construct the envelope models which are fully radiaitive…

Astrophysics · Physics 2009-11-10 U. Lee

We propose a methodological framework to perform forward asteroseismic modeling of stars with a convective core, based on gravity-mode oscillations. These probe the near-core region in the deep stellar interior. The modeling relies on a set…

We examine pulsational stability of low $m$ $r$ modes in SPB stars by calculating fully nonadiabatic oscillations of uniformly rotating stars, where $m$ is an integer representing the azimuthal wave number around the rotation axis. $R$…

Astrophysics · Physics 2009-11-13 Umin Lee

We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the Sun, using three separate approaches: 1) Using the 3-D planar StellarBox radiation hydrodynamics code to model the…

Solar and Stellar Astrophysics · Physics 2016-05-17 Joyce A. Guzik , T. H. Morgan , N. J. Nelson , C. Lovekin , K. Kosak , I. N. Kitiashvili , N. N. Mansour , A. Kosovichev

We have performed a linear pulsational stability survey of 6 series of long period variable models with M=1.0 Msun, L=3000 - 8000Lsun, and (X,Z)= (0.700,0.020),(0.735,0.005). The dynamic and thermodynamic couplings between convection and…

Astrophysics · Physics 2009-10-30 D. R. Xiong , L. Deng , Q. L. Cheng

Spectroscopic studies of Galactic O and B stars show that many stars with masses above 8 M$_{\odot}$ are observed in the HR diagram just beyond the Main-Sequence (MS) band predicted by stellar models computed with a moderate overshooting.…

The relation of period spacing ($\Delta P$) versus period ($P$) of dipole prograde g modes is known to be useful to measure rotation rates in the g-mode cavity of rapidly rotating $\gamma$ Dor and slowly pulsating B (SPB) stars. In a…

Solar and Stellar Astrophysics · Physics 2021-03-03 Hideyuki Saio , Masao Takata , Umin Lee , Gang Li , Timothy Van Reeth

We study the conditions for convective instability in rotating, non-magnetic proto--neutron stars. The criteria that determine stability of nascent neutron stars are analogous to the Solberg--Hoiland conditions but including the presence of…

Astrophysics · Physics 2009-11-10 J. A. Miralles , J. A. Pons , V. Urpin

Both observations and numerical simulations show that stellar convective motions are composed of semi-regular flows of convective rolling cells and the fully developed turbulence. Although the convective rolling cells are crucial for the…

Solar and Stellar Astrophysics · Physics 2015-06-04 Yan Li

We present a detailed analysis of the dynamics of proto-compact star (PCS) convection and the core ${}^2\!g_1$-mode in core-collapse supernovae based on general relativistic 2D and 3D neutrino hydrodynamics simulations. Based on 2D…

High Energy Astrophysical Phenomena · Physics 2025-05-23 Pia Jakobus , Bernhard Mueller , Alexander Heger

We predict the flux and surface velocity perturbations produced by convectively excited gravity modes (g-modes) in main sequence stars. Core convection in massive stars can excite g-modes to sufficient amplitudes to be detectable with high…

Solar and Stellar Astrophysics · Physics 2015-06-11 Joshua H. Shiode , Eliot Quataert , Matteo Cantiello , Lars Bildsten

Recent observational results from asteroseismic studies show that an important fraction of solar-like stars do not present detectable stochastically excited acoustic oscillations. This non-detectability seems to correlate with a high…

Solar and Stellar Astrophysics · Physics 2025-07-30 Leïla Bessila , Adrien Deckx van Ruys , Valentin Buriasco , Stéphane Mathis , Lisa Bugnet , Rafael A. García , Savita Mathur

Rotational evolution in the pre-main sequence (PMS) is described with new sets of PMS evolutionary tracks including rotation, non-gray boundary conditions (BCs) and either low (LCE) or high convection efficiency (HCE). Using observational…

Some physical processes that occur during a star's main-sequence evolution also affect its post main-sequence evolution. It is well known that stars with masses above approximately 1.1 $M_{\odot}$ have well-mixed convective cores on the…

Solar and Stellar Astrophysics · Physics 2024-02-21 Christopher J. Lindsay , J. M. Joel Ong , Sarbani Basu

In order to understand the periodic and semi-periodic variations of luminous O- B- A-type stars, linear nonadiabatic stability analyses for radial and nonradial oscillations have been performed for massive evolutionary models ($8M_\odot -…

Solar and Stellar Astrophysics · Physics 2015-05-20 Hideyuki Saio

The rotational properties of centrally condensed, turbulent molecular cloud cores with velocity fields that are characterized by Gaussian random fields are investigated. It is shown that the observed line width-size relationship can be…

Astrophysics · Physics 2009-10-31 Andreas Burkert , Peter Bodenheimer
‹ Prev 1 2 3 10 Next ›