We report the identification of SH ∆v = 1 ro-vibrational lines in the published high-resolution infrared spectrum of the S-type star, R And. This is the first astronomical detection of this molecule. The lines show inverse P-Cygni profiles, indicating infall motion of the molecular layer due to stellar pulsation. A simple spherical shell model with a constant infall velocity is adopted to deter...

The ISO/SWS spectrum of o Cet taken at its maximum exhibits an absorption-like feature between 3.5 and 4.0 μm. We present evidence that the feature is due to emission of H2O and SiO molecules, in a layer extended to about two stellar radii with an excitation temperature of 2000 K. These hot molecules are also observed in a spectrum of Z Cas near minimum, but this time in absorption. A simple pl...

Over the past two decades, helioseismology has revolutionized our understanding of the interior structure and dynamics of the Sun. Asteroseismology will soon place this knowledge into a broader context by providing structural data for hundreds of Sun-like stars. Solar-like oscillations have already been detected from the ground in several stars, and NASA’s Kepler mission is poised to unleash a ...

Over the past two decades, helioseismology has revolutionized our understanding of the interior structure and dynamics of the Sun. Asteroseismology will soon place this knowledge into a broader context by providing structural data for hundreds of Sun-like stars. Solar-like oscillations have already been detected from the ground in several stars, and NASA’s Kepler mission is poised to unleash a ...

The identification of non-radial g-mode oscillations as the cause of variability in cool subdwarf B stars (PG1716 variables) has been frustrated by a 5 000K discrepancy between the observed and theoretical blue edge of the instability domain (Fontaine et al. 2003). A major component in the solution to this problem has been identified by (a) using updated OP instead of OPAL opacities and (b) con...

We present a finite difference code intended for computing linear, adiabatic, nonradial pulsations of spherical stars. This code is based on a slight modification of the general Newton-Raphson technique in order to handle the relaxation of the eigenvalue (square of the eigenfrequency) of the modes and their corresponding eigenfunctions. This code has been tested computing the pulsation spectra ...

In this work, we present the theoretically expected rates of pulsation period change for V777 Her (DBV) variable stars. To this end we employ new evolutionary models representative of pulsating DB white dwarf stars computed in a self-consistent way with the predictions of time-dependent element diffusion. At the hot edge of the DB instability strip, the envelopes of the models are characterized...

It is inferred from the symmetrical and luminous X-ray emission of fossil groups that they are mature, relaxed galaxy systems. Cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. Recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (BGGs), the central early-t...

Aims. We searched the SuperWASP archive for objects that display multiply periodic photometric variations. Methods. Speci cally we sought evidence for eclipsing binary stars that display a further non-harmonically related signal in their power spectra. Results. The object 1SWASP J050634.16 353648.4 has been identi ed as a relatively bright (V ∼ 11.5) semi-detached eclipsing binary with a 5.104 ...

Aims. We searched the SuperWASP archive for objects that display multiply periodic photometric variations. Methods. Speci cally we sought evidence for eclipsing binary stars that display a further non-harmonically related signal in their power spectra. Results. The object 1SWASP J050634.16 353648.4 has been identi ed as a relatively bright (V ∼ 11.5) semi-detached eclipsing binary with a 5.104 ...