Related papers: The triple-mode pulsating variable V823 Cas
We have analysed high-precision photometry of 77 double-mode RR Lyrae (RRd) stars observed by NASA's Kepler-K2 mission during Campaigns 1-18. Among those stars, we have identified several low-period ratio variables, belonging either to a…
Combination frequencies are not solutions of the perturbed stellar structure equations. In dense power spectra from a light curve of a given multi-periodic pulsating star, they can compromise the mode identification in an asteroseismic…
PG 1159-035, a pre-white dwarf with T=140000 K, is the prototype of the PG1159 spectroscopic class and the DOV pulsating class. Changes in the star cause variations in its oscillation periods. The measurement of temporal change in the…
A new method is presented here for evaluating approximately the pulsation modes of relativistic stellar models. This approximation relies on the fact that gravitational radiation influences these modes only on timescales that are much…
R-modes of a rotating neutron star are unstable because of the emission of gravitational radiation. We explore the saturation amplitudes of these modes determined by nonlinear mode-mode coupling. Modelling the star as incompressible allows…
Recent re-determination of stellar atmospheric parameters for a sample of stars observed during the {\it Kepler} mission allowed to enlarge the number of {\it Kepler} B-type stars. We present the detailed frequency analysis for all these…
A new effect originating from the crystal-field-excitation - phonon coupling was observed (in the far infrared spectra of a multiferroic PrFe3(BO3)4). The reststrahlen band corresponding to the A2 symmetry nondegenerate phonon mode near 50…
We use time- and angle-resolved photoemission spectroscopy (tr-ARPES) in the Extreme Ultraviolet (EUV) to measure the time- and momentum-dependent electronic structure of photo-excited K0.3MoO3. Prompt depletion of the Charge Density Wave…
The quasi-periodic feature of 1-10 years exhibited in pulsar timing noise has not been well understood since 1980. The recently demonstrated correlation between timing noise and variation of pulse profile motivates us to further investigate…
This paper analyzes the first secured four color light curves of V396 Mon using the 2003 version of the WD code. It is confirmed that V396 Mon is a shallow W-type contact binary system with a mass ratio $q=2.554(\pm0.004)$ and a degree of…
Sample-to-sample fluctuations of the time-dependent conductance of a system with static disorder have been studied by means of diagrammatic theory and microwave pulsed transmission measurements. The fluctuations of time-dependent…
We review methodologies currently available to interprete time series of high-resolution high-S/N spectroscopic data of pulsating stars in terms of the kind of (non-radial) modes that are excited. We illustrate the drastic improvement of…
Calculations for spin-phonon coupling constants in CuGeO3 are presented, applying fourth order superexchange perturbation theory to an extended Hubbard model. In our treatment, the intermediate oxygen ligand states are described by…
Pulsating binary stars are ideal targets for testing the theory of stellar structure and evolution. Fundamental parameters can be derived to high precision from binary modelling and provide crucial constraints for seismic modelling.…
PG 1159-035 is the prototype of the DOV hot pre-white dwarf pulsators. It was observed during the Kepler satellite K2 mission for 69 days in 59 s cadence mode and by the TESS satellite for 25 days in 20 s cadence mode. We present a detailed…
While there are many dynamical mechanisms and models that try to explain the origin and phenomenology of the quasi-periodic oscillations (QPOs) seen in the X-ray light curves of low-mass X-ray binaries, few of them address how the radiative…
This is a progress report on our study of the coupling of first-order radial and non-radial relativistic perturbations of a static spherical star. Our goal is to investigate the effects of this coupling on the gravitational wave signal of…
The mode switching phenomenon of PSR J0614+2229 was studied by using the archived observations at 686, 1369 and 3100 MHz with the Parkes radio telescope which have not been published before, and combining existing observations from the…
We report the most rapid rate of period change measured to date for a pulsating DA (hydrogen atmosphere) white dwarf (WD), observed in the 292.9 s mode of WD 0111+0018. The observed period change, faster than 10^{-12} s/s, exceeds by more…
We briefly review progress in developing a pathway to nonlinear astereoseismology, both from theoretical and observational aspects. As predicted by the theory of weak nonlinear interactions between resonant modes, their amplitude and…