相关论文: Low-dimensional chaos in RR Lyrae models

We present N-body simulations of resonant planets with inclined orbits that show chaotically evolving eccentricities and inclinations that can persist for at least 10 Gyr. A wide range of behavior is possible, from fast, low amplitude…

The results of numerical experiments on chaotic ('turbulent') dynamics of the second sound in helium II are presented and discussed based on a very simple model proposed and theoretically studied recently by Khalatnikov and Kroyter. Using a…

The light curves of the two large amplitude variable stars, R Scuti and AC Herculis, display irregular pulsation cycles with 'periods' of 75 and 35 days, respectively. We review the evidence that the observed time-series are generated by…

The long therm behavior of chaotic flows is investigated by means of time dependent frequency analysis. The system under test consists of an electrically conducting fluid, confined between two differentially rotating spheres. The spherical…

Recent work on many particle system reveals the existence of regular collective perturbations corresponding to the smallest positive Lyapunov exponents (LEs), called hydrodynamic Lyapunov modes. Until now, however, these modes are only…

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…

The Luminous Blue Variable stars exhibit behavior ranging from light curve `microvariations' on timescales of tens of days, to `outbursts' accompanied by mass loss of up to 10e-03 solar masses per year, occurring decades apart, to `giant…

A recently introduced chaos detection method, the Relative Lyapunov Indicator (RLI) is investigated in the cases of symplectic mappings and continuous Hamiltonian systems. It is shown that the RLI is an efficient numerical tool in…

We use the pulsational properties of the RR Lyrae variables in the globular cluster NGC 1851 to obtain detailed constraints of the various sub-stellar populations present along its horizontal branch. On the basis of detailed synthetic…

We present an analysis of the lightcurve extracted from Transiting Exoplanet Survey Satellite Full Frame Images of the double-mode RR Lyrae V338 Boo. We find that the fundamental mode pulsation is changing in amplitude across the 54 days of…

We present the results of a photometric study of RR Lyrae variables in the field of the globular cluster M55. We have discovered nine new RR Lyrae stars, increasing the number of known variables in this cluster to 15 objects. Five of the…

RRab stars are large amplitude pulsating stars in which the pulsation is associated with strong shock wake propagating in the atmosphere. The objective of this study is to provide a general overview of the dynamical structure of the…

Local bifurcations of stationary points and limit cycles have successfully been characterized in terms of the critical exponents of these solutions. Lyapunov exponents and their associated covariant Lyapunov vectors have been proposed as…

In this article, on the example of the known low-order dynamical models, namely Lorenz, Rossler and Vallis systems, the difficulties of reliable numerical analysis of chaotic dynamical systems are discussed. For the Lorenz system, the…

Space-based photometric measurements first revealed low-amplitude irregularities in the pulsations of Cepheid stars, but their origins and how commonly they occur remain uncertain. To investigate this phenomenon, we present MOST space…

Astrophysical objects frequently exhibit some irregularities or complex behaviour in their light curves. We focus primarily on hot stars, where both radial and non-radial pulsations are observed. One of the primary research goals is to…

The observations of the photometric space telescopes CoRoT and Kepler show numerous Blazhko RR Lyrae stars which have non-repetitive modulation cycles. The phenomenon can be explained by multi-periodic, stochastic or chaotic processes. From…

It is shown, that at weakly nonlinear interaction of waves are possible as modes with chaotic dynamics, and with increasing degree of coherence. Conditions are found at which they arise. One of the types of such interaction is decays. The…

The results of nonlinear, convective models of RR Lyrae pulsators with metal content Z=0.0001 to 0.006 are discussed and several predicted relations connecting pulsational (period and amplitude of pulsation) and evolutionary parameters…

We collected over 6000 high-resolution spectra of four dozen field RR Lyrae (RRL) variables pulsating either in the fundamental (39 RRab) or in the first overtone (9 RRc) mode. We measured radial velocities (RVs) of four strong metallic and…