Pulsation powered by deuterium burning in brown dwarfs and very low mass stars has been put forth (Palla & Baraffe 2005) as a novel probe of the interiors of these objects in the 1-15 Myr age range. Previous observations have hinted at variability on the expected timescales of a few hours, suggesting but not confinning that the phenomenon is at work in young brown dwarfs. We have recently carri...

Context. Stellar oscillations are an important tool to probe the interior of a star. Subdwarf B stars are core helium burning objects, but their formation is poorly understood as neither single star nor binary evolution can fully explain their observed properties. Since 1997 an increasing number of sdB stars has been found to pulsate forming two classes of stars (the V361 Hya and V1093 Her star...

We present new theoretical Period-Radius (PR) relations for first overtone Galactic Cepheids. Current predictions are based on several sequences of nonlinear, convective pulsation models at solar chemical composition (Y=0.28, Z=0.02) and stellar masses ranging from 3.0 to 5.5 M . The comparison between predicted and empirical radii of four short-period Galactic Cepheids suggests that QZ Nor and...

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 best-fitting 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 componen...

Comparative linear nonadiabatic pulsation calculations are presented using the OPAL and Opacity Project opacities. The two sets of opacities include effects due to intermediate coupling and fine structure as well as new abundances. We used two mass luminosity (M L) relations, one standard (BIT), and one employing substantial convective core overshoot (CO V). The two sets of opacities cannot be ...

Interpretation of the available ground-based and forthcoming space observations of multiperiodic variable stars require accurate computations of oscillation frequencies. Typical rotational equatorial velocities of upper main sequence stars range between 50 and 200 km/s and the effect of rotation on the oscillation frequencies of these stars must be included. The rotation can still be considered...

We have computed stellar evolutionary models for stars in a mass range characteristic of Cepheid variables (3 < m/M < 12) for different metallicities representative of the Galaxy and the Magellanic Clouds populations. The stellar evolution calculations are coupled to a linear non adiabatic stability analysis to get self-consistent mass-period-luminosity relations. The period luminosity relation...

Phase differences and amplitude ratios at different colour photometric bands are currently being used to discriminate pulsation modes in order to facilitate mode identification of κ-driven non-radial pulsating stars. In addition to physical inputs (e.g., mass, T e f f , etc.), these quantities depend on the non-adiabatic treatment of the atmosphere. This paper presents theoretical results conce...