Aims. We present an asteroseismological study on the two high-gravity pulsating PG1159 (GW Vir or DOV) stars, PG 2131+066 and PG 1707+427, and on the pulsating [WCE] star NGC 1501. All of these stars have been intensively scrutinized through multi-site observations, so they have well resolved pulsation spectra. Methods. We compute adiabatic g-mode pulsation periods on PG1159 evolutionary models...

We discuss the possibilities to derive the pulsation parameters ` andm of non-radially pulsating rotating stars from spectroscopic observations.Wemodel the line-profile variations caused by the oscillatory velocity field and temperature variations at the surface of the star. In our description of the velocity field of the pulsations, we use the expressions for linear adiabatic pulsations, and i...

Context. There are many unknowns surrounding the formation of subdwarf B stars, and different formation channels are considered to be possible. Nevertheless, seismic models up to date assume that an sdB star is a post-helium-flash-core surrounded by a thin inert layer of hydrogen. Aims. We examine an alternative formation channel, in which the sdB star originates from a massive (> ∼2 M ) Red Gi...

We aim to investigate the IR excess of 45 MW Cepheids combining different observables constrain presence CSE. used SPIPS algorithm, a robust implementation parallax-of-pulsation method that combines photometry, angular diameter, stellar effective temperature, and RV measurements in global modelling pulsation. obtained new photometric at mid-IR with VLT/VISIR complemented literature data. then c...

AB S TRACT A global analysis of the surface trapping of low-frequency non-radial g modes in rotating early-type stars is undertaken within the Cowling, adiabatic and traditional approximations. The dimensionless pulsation equations governing these modes are reviewed, and the boundary conditions necessary for solution of the equations are considered; in particular, an outer mechanical boundary c...

We have derived a set of equations to describe the thermal evolution of a neutron star which undergoes small-amplitude radial pulsations. We have taken into account, in the frame of the General Theory of Relativity, the pulsation damping due to the bulk and shear viscosity and the accompanying heating of the star. The neutrino emission of a pulsating non-superfluid star and its heating due to t...

We report the discovery of the first high-amplitude δ Scuti star in an eclipsing binary, which we have designated UNSW-V-500. The system is an Algol-type semi-detached eclipsing binary of maximum brightness V = 12.52 mag. A bestfitting solution to the binary light curve and two radial velocity curves is derived using the Wilson-Devinney code. We identify a late A spectral type primary component...

Using our non-local time-dependent theory of convection, the linear non-adiabatic oscillations of 10 evolutionary model series with masses of 1–3M⊙ are calculated. The results show that there is a red giant instability strip in the lower temperature side of the Hertzsprung-Russel (HR) diagram which goes along the sequences of the red giant branch (RGB) and the asymptotic giant branch (AGB). For...

Hot, luminous, massive stars have strong stellar winds driven by line-scattering of the star’s continuum radiation. They are also often observed to exhibit radial or non-radial pulsations. Such pulsations are possible candidates for providing the base perturbations that induce large-scale structure in the overlying wind, and as such they could help explain various observational manifestions of ...