Using high-resolution, moderate signal-to-noise ratio spectroscopy obtained with the 10 m Keck I Telescope and efficient HIRES echelle spectrograph, we derive abundances of several elements in subgiants near the M92 turno†. As a consistency check, we also analyze the metal-poor Ðeld star HD 140283 and Ðnd an Fe abundance in Ðne agreement with many previous determinations. However, our M92 value...

Context. The evolution of the Milky Way bulge and its relationship with the other Galactic populations is still poorly understood. The bulge has been suggested to be either a merger-driven classical bulge or the product of a dynamical instability of the inner disk. Aims. To probe the star formation history, the initial mass function and stellar nucleosynthesis of the bulge, we performed an elem...

Oscillations of the Sun and solar-like stars are believed to be excited stochastically by convection near the stellar surface. Theoretical modeling predicts that the resulting amplitude increases rapidly with the luminosity of the star. Thus one might expect oscillations of substantial amplitudes in red giants with high luminosities and vigorous convection. Here we present evidence that such os...

Assuming that in the atmospheres of low-mass, metal-poor red giant stars, onedimensional models based on local thermodynamic equilibrium accurately predict the abundance of iron from Fe ii, we derive a globular cluster metallicity scale based on the equivalent widths of Fe ii lines measured from high resolution spectra of giants in 16 key clusters lying in the abundance range –2.4 < [Fe/H]II < ...

This is the first of a series of papers devoted to derive the metallicity of old open clusters in order to study the time evolution of the chemical abundance gradient in the Galactic disk. We present detailed iron abundances from high resolution (R ∼ > 40, 000) spectra of several red clump and bright giant stars in the open clusters IC 4651, NGC 2506 and NGC 6134. We observed 4 stars of NGC 250...

New CORAVEL radial-velocity observations and UBV photometry of 24 red giants in the field of the intermediate-age open cluster Mel 71 are analysed for membership and duplicity. The membership of 16 stars is confirmed, one star is a possible member, and 8 spectroscopic binaries have been discovered , all amongst the cluster stars. Four of their orbits have been determined, with periods ranging f...

High resolution spectra of 123 red giant stars in the globular cluster M13 and 64 red giant stars in M92 were obtained with Hectochelle at the MMT telescope. Emission and line asymmetries in Hα, and Ca II K are identified, characterizing motions in the extended atmospheres and seeking differences attributable to metallicity in these clusters and M15. On the red giant branch, emission in Hα gene...

Abstract In this work, we studied the distribution of lithium abundances in giants as a function stellar mass. We used sample 1240 common among Kepler photometric and LAMOST medium-resolution ( R ? 7500) spectroscopic survey fields. The asteroseismic ? P –? ? diagram is to define core He-burning red clump giant branch stars with an inert He core. Li have been derived using spectral synthesis fo...