Related papers: The effect of convection on pulsational stability
We present a seismic study of $\delta$ Scuti based on a mode identification from multicoulor photometry. The dominant frequency can be associated only with a radial mode and the second frequency is, most probably, a dipole mode. The other…
The dynamics of magnetic moments consist of a precession around the magnetic field direction and a relaxation towards the field to minimize the energy. While the magnetic moment and the angular momentum are conventionally assumed to be…
We evaluate the impact of the rotation on the stochastic excitation of acoustic (p) modes in solar-like pulsators. First, we derive the forced wave equation taking rotation into account and we compute the source terms, which inject energy…
Using a nonlocal time-dependent theory of convection, we have calculated the linear non-adiabatic oscillations of the Horizontal Branch (HB) stars, with both the dynamic and thermodynamic coupling between convection and oscillations…
Pulsars are good clocks in the universe. One fundamental question is that why they are good clocks? This is related to the braking mechanism of pulsars. Nowadays pulsar timing is done with unprecedented accuracy. More pulsars have braking…
We study the effects of a static and uniform magnetic field on the evolution of energy density fluctuations present in a medium. By numerically solving the relativistic Boltzmann-Vlasov equation within the relaxation time approximation, we…
Inertial modes have been observed on the Sun at low longitudinal wavenumbers. These modes probe the dynamics and structure of the solar convection zone down to the tachocline. While linear analysis allows the complex eigenfrequencies and…
A review on acoustic mode damping and excitation in solar-type stars is presented. Current models for linear damping rates are discussed in the light of recent low-degree solar linewidth measurements with emphasis on the…
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…
We consider dissipative one-dimensional systems subject to a periodic force and study numerically how a time-varying friction affects the dynamics. As a model system, particularly suited for numerical analysis, we investigate the driven…
We investigate the pulsational stability of massive (M >~ 120 Msun) main sequence stars of a range of metallicities, including primordial, Population III stars. We include a formulation of convective damping motivated by numerical…
We use moment method developed by Balona (1987) to identify the dominant mode of the multimode pulsating Delta Scuti star X Cae. It is shown as a l=1 and m=-1 non-radial mode gives a satisfactory fit of the amplitudes and phases of light…
We study the effects of rotation on the torsional modes of oscillating relativistic stars with a solid crust. Earlier works in Newtonian theory provided estimates of the rotational corrections for the torsional modes and suggested that they…
In the present paper we consider convection and cracking instabilities as well as their interplay. We develop a simple criterion to identify equations of state unstable to convection, and explore the influence of buoyancy on cracking (or…
We analyze the collective behavior of a lattice model of pulse-coupled oscillators. By studying the intrinsic dynamics of each member of the population and their mutual interactions we observe the emergence of either spatio-temporal…
We identify stars in the $\delta$ Sct instability strip that do not pulsate in p modes at the 50-$\mu$mag limit, using Kepler data. Spectral classification and abundance analyses from high-resolution spectroscopy allow us to identify…
We calculate detailed modification of pulses from a pulsar arising from the effects of phase transition induced density fluctuations on the pulsar moment of inertia. We represent general statistical density fluctuations using a simple model…
We investigate the dynamics of the pendulum suspended on the forced Duffing oscillator. The detailed bifurcation analysis in two parameter space (amplitude and frequency of excitation) which presents both oscillating and rotating periodic…
It has been recently shown numerically that a small-scale dynamo (SSD) instability could be possible in solar-like low magnetic Prandtl number plasmas. It has been proposed that the presence of SSD can potentially have a significant impact…
The influence of fluctuating conductivity on the coefficients known from the mean-field electrodynamics is considered. If the conductivity fluctuations are assumed as uncorrelated with the turbulent velocity field then only the effective…