The GGSS is a partially-filled, all-sky survey to identify K-giant stars with low level of RV-variability. We study histograms of the radial velocity (RV) variability obtained in the early phase of the Grid Giant Star Survey (GGSS, Bizyaev et al., 2006). This part of the survey has been conducted with a very limited nubmer of observations per star, and rough accuracy. We apply the Monte-Carlo s...

Context. Solar-like oscillations have been observed in numerous red giants from ground and from space. An important question arises: could we expect to detect non-radial modes probing the internal structure of these stars? Aims. We investigate under what physical circumstances non-radial modes could be observable in red giants; what would be their amplitudes, lifetimes and heights in the power ...

Context. Solar-like oscillations have been observed in numerous red giants from ground and from space. An important question arises: could we expect to detect non-radial modes probing the internal structure of these stars? Aims. We investigate under what physical circumstances non-radial modes could be observable in red giants; what would be their amplitudes, lifetimes and heights in the power ...

Molecular bands have been used as a diagnostic of spectral type since the 1860's. TiO was first identified as the dominant feature in optical spectra of cool giants in 1904 (Fowler 1904). Many diatomic molecules have now been included (e.g. J0rgensen & Larsson 1990) in detailed calculations of stellar opacity and attention is starting to focus on the incorporation of accurate data for triatomic...

Context. Diffusion of atoms can be important during quiescent phases of stellar evolution. Particularly in the very thin inert envelopes of subdwarf B stars, diffusive movements will considerably change the envelope structure and the surface abundances on a short timescale. Also, the subdwarfs will inherit the effects of diffusion in their direct progenitors, namely giants near the tip of the r...

We have studied the stellar population and internal structure of the core of the Ursa Minor dwarf spheroidal galaxy, using a sample of stars selected to be members based on their proper motions. In agreement with previous studies, we find Ursa Minor to be dominated by an old, metal-poor stellar population. A small number of stars with high membership probabilities lie redward of the red giant b...

Context. Since 1999, we have been conducting a radial velocity survey of 179 K giants using the Coudé Auxiliary Telescope at UCO/Lick observatory. At present ∼20−100 measurements have been collected per star with a precision of 5 to 8 m s−1. Of the stars monitored, 145 (80%) show radial velocity (RV) variations at a level >20 m s−1, of which 43 exhibit significant periodicities. Aims. Our aim i...

The set of orbital elements available for chemically-peculiar red giant (PRG) stars has been considerably enlarged thanks to a decade-long CORAVEL radial-velocity monitoring of about 70 barium stars and 50 S stars. When account is made for the detection biases, the observed binary frequency among strong barium stars, mild barium stars and Tc-poor S stars (respectively 35/37, 34/40 and 24/28) is...

Those massive stars that, during their deaths, give rise to gamma-ray bursts (GRBs) must be endowed with an unusually large amount of angular momentum in their inner regions, one to two orders of magnitude greater than the ones that make common pulsars. Yet the inclusion of mass loss and angular momentum transport by magnetic torques during the precollapse evolution is known to sap the core of ...