Related papers: What have we learnt from pulsations of B-type star…
Since the early nineties it is accepted that the excitation mechanism of B-type pulsators on the main sequence is due to the opacity peak in the iron-group elements at $T\approx 200,000$ K. The Fe content plays then a major role in the…
We suggest that high-order g modes can be used as a probe of the internal magnetic field of SPB (slowly pulsating B) stars. The idea is based on earlier work by the authors which analytically investigated the effect of a vertical magnetic…
We present a comprehensive seismic study of the three pulsating stars of $\beta$ Cep/SPB type: $\nu$ Eridani, 12 Lacertae and $\gamma$ Pegasi. Models with the modified mean opacity profile are constructed in order to account for both the…
We examine the role of opacities in stellar pulsation with reference to Cepheids and RR Lyraes, and examine the effect of augmented opacities on the theoretical pulsation light curves in key temperature ranges. The temperature ranges are…
Stellar pulsations in main-sequence B-type stars are driven by the $\kappa$-mechanism due to the Fe-group opacity bump. The current models do not predict the presence of instability strips in the B spectral domain at very low metallicities.…
Interpretation of the oscillation spectrum of the slowly pulsating B-type star HD21071 is presented. We show that non-rotating models cannot account for the two highest amplitude frequencies and taking into account the effects of rotation…
The slowly pulsating B (SPB) stars are a class of variable star with masses between about 3 and 8 M$_{\odot}$. Their gravity-mode pulsation frequencies are sensitive to the near-core structure, which makes them useful probes of rotation and…
The mixing of material from stellar convective cores into their adjacent radiative layers has been a matter of long-standing debate. Pulsating subdwarf B stars offer excellent conditions to advance our understanding of this problem. In this…
We present our analyses of 15 months of Kepler data on KIC 10139564. We detected 57 periodicities with a variety of properties not previously observed all together in one pulsating subdwarf B star. Ten of the periodicities were found in the…
The analysis of the BRITE oscillation spectrum of the main sequence early B-type star $\nu$ Eridani is presented. Only models with the modified mean opacity profile can account for the observed frequency ranges as well as for the values of…
An overview of selected topical problems on modelling oscillation properties in solar-like stars is presented. High-quality oscillation data from both space-borne intensity observations and ground-based spectroscopic measurements provide…
Massive stars are important building blocks of the Universe, and their stellar structure and evolution models are fundamental cornerstones of various fields in modern astrophysics. The precision of these models is limited by our lack of…
In the context of the determination of stellar properties using asteroseismology, we study the influence of rotation and convective-core overshooting on the properties of red-giant stars. We used models in order to investigate the effects…
Stellar pulsations in main-sequence B-type stars are driven by the $\kappa$-mechanism due to the Fe-group opacity bump. The current models do not predict the presence of instability strips in the B spectral domain at very low metallicities.…
During the course of an ongoing CCD monitoring program to investigate low-level light variations in subdwarf B (sdB) stars, we have serendipitously discovered a new class of low amplitude, multimode sdB pulsators with periods of the order…
Rapidly oscillating Ap stars are unique objects in the potential they offer to study the interplay between a number of important physical phenomena, in particular, pulsations, magnetic fields, diffusion, and convection. Nevertheless, the…
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…
r-mode oscillations have been shown to have a significant potential to constrain the composition of fast spinning neutron stars. Due to their high rotation rates, millisecond pulsars (MSPs) provide a unique platform to constrain the…
We present optical time series spectroscopy of the pulsating white dwarf star G29-38 taken at the Very Large Telescope (VLT). By measuring the variations in brightness, Doppler shift, and line shape of each spectrum, we explore the physics…
We investigate the pulsation properties of stellar models representative of $\delta$ Scuti and $\gamma$ Doradus variables. We have calculated a grid of stellar models from 1.2 to 2.2 M$_{\odot}$, including the effects of both rotation and…