Related papers: The triple-mode pulsating variable V823 Cas

Pulsators on and near the main sequence show period and amplitude changes that are too large to be the product of stellar evolution. The multiperiodic Delta Scuti stars are well suited to study these changes. This requires a very large…

The OGLE project led to discovery of earlier unknown forms of multiperiodic pulsation in Cepheids. Often, the observed periods may be explained in terms of simultaneous excitation of two or rarely three radial modes. However, a secondary…

We have carried out a study of the orthogonal polarisation mode behaviour as a function of frequency of 18 pulsars, using average pulsar data from the European Pulsar Network (EPN). Assuming that the radiation consists of two 100% polarised…

We present a theoretical investigation on periods and amplitudes of RR Lyrae pulsators by adopting stellar parameters which cover the range of theoretical evolutionary expectations. Extensive grids of nonlinear, nonlocal and time-dependent…

We explore the nonlinear coupling of the three scissors modes of an anisotropic Bose-Einstein condensate. We show that only when the frequency of one of the scissors modes is twice the frequency of another scissors mode, these two modes can…

The measurements of pulsar frequency second derivatives have shown that they are 1e2...1e6 times larger than expected for standard pulsar spin-down law. Moreover, the second derivatives as well as braking indices are even negative for about…

We present a phenomenological analysis of long-period variables (LPVs) in the Large Magellanic Cloud with the aim of detecting pulsation modes associated to different period-luminosity (PL) relations. Among brighter LPVs we discover a group…

Analyses of multiple pulse sequences of B2303+30 reveal that this pulsar has two distinct emission modes. One mode (B) follows a steady even-odd pattern and is more intense. The second mode (Q) is characteristically weak, but has…

We present TESS photometry of the triple star system V1031 Ori (AB)C, which exhibits short-period oscillations superimposed on an eclipsing light curve. The high-quality data were analyzed in detail and combined with the published…

Previously, a series of tidally-excited oscillations were discovered in the eccentric eclipsing binary KIC 3230227. The pulsation amplitudes and phases suggest the observed oscillations are prograde quadruple modes. In this paper, we refine…

Free electrons in the interstellar medium refract and diffract radio waves along multiple paths, resulting in angular and temporal broadening of radio pulses that limits pulsar timing precision. We determine multifrequency, multi-epoch…

Rotating Radio Transients (RRATs) are a class of pulsar-like objects characterized by intermittent radio emissions. Among them, RRATs that exhibit both RRAT and normal pulsar (NP) states may represent a key evolutionary stage from nulling…

The standard theory of pulsations deals with the frequencies and growth rates of infinitesimal perturbations in a stellar model. Modes which are calculated to be linearly driven should increase their amplitudes exponentially with time; the…

The carousel model of pulsar emission attributes the phenomenon of subpulse drifting to a set of discrete sparks located very near the stellar surface rotating around the magnetic axis. Here, we investigate the subpulse drifting behaviour…

This work investigates the behavior of an AlGaAs/GaAs piezoelectric nonlinear MEMS oscillator exhibiting a 1:3 internal resonance. The device is explored in an open-loop configuration, i.e. as a driven resonator, where depending on the…

We analyze the frequencies of three known roAp stars, TIC 96315731, TIC 72392575, and TIC 318007796, using the light curves from the Transiting Exoplanet Survey Satellite (TESS). For TIC 96315731, the rotational and pulsational frequencies…

Using new techniques based on the polarimetric fluctuation spectrum, the fluctuation behaviour of the polarization of individual pulses is examined in three pulsars that show drifting subpulses, allowing various aspects of the fluctuations…

Nanomechanical and other mesoscopic vibrational systems typically have several nonlinearly coupled modes with different frequencies and with long lifetime. We consider the power spectrum of one of these modes. Thermal fluctuations of the…

We present the analysis of four first overtone RR Lyrae stars observed with the Kepler space telescope, based on data obtained over nearly 2.5yr. All four stars are found to be multiperiodic. The strongest secondary mode with frequency f_2…

We have investigated the mode-changing properties of PSR B0329+54 using 31 epochs of simultaneous 13 cm/3 cm single-pulse observations obtained with Shanghai Tian Ma 65 m telescope. The pulsar was found in the abnormal emission mode 17…