Intrinsic iron spread and a new metallicity scale for Globular Clusters (2009)
Carretta, Eugenio, Bragaglia, Angela, Gratton, Raffaele, D'Orazi, Valentina, Lucatello, Sara
We have collected spectra of about 2000 red giant branch (RGB) stars in 19 Galactic globular clusters (GC) using FLAMES@VLT (about 100 star with GIRAFFE and about 10 with UVES, respectively, in each...
Carretta, Eugenio, Bragaglia, Angela, Gratton, Raffaele, Lucatello, Sara
We present homogeneous abundances for Fe and some of the elements involved in the proton-capture reactions (O, Na, Mg, Al, and Si) for 202 red giants in 17 Galactic globular clusters (GCs) from the...
Properties of second generation stars in Globular Clusters (2008)
Carretta, Eugenio, Bragaglia, Angela, Gratton, Raffaele G., Lucatello, Sara
We present the first results from the analysis of GIRAFFE spectra of more than 1200 red giants stars in 19 Galactic Globular Clusters (GCs), to study the chemical composition of second generation...
Carretta, Eugenio, Recio-Blanco, Alejandra, Gratton, Raffaele G., Piotto, Giampaolo, Bragaglia, Angela
We find a strong correlation between the extension of the Na-O anticorrelation observed in red giant branch (RGB) stars and the high temperature extension of the horizontal branch (HB) blue tails of...
The chemical abundance of the very metal rich old Open Clusters NGC 6253 and NGC 6791 (2007)
Carretta, Eugenio, Bragaglia, Angela, Gratton, Raffaele
In the framework of a project aiming at deriving in a homogeneous way the properties (age, distance, reddening and detailed chemical abundances) of a large sample of old open clusters, we present...
Variations in the lithium abundances of turn off stars in the globular cluster 47 Tuc (2007)
Bonifacio, Piercarlo, Pasquini, Luca, Molaro, Paolo, Carretta, Eugenio, François, Patrick, Gratton, Raffaele G., ...
aims: Our aim is to determine Li abundances in TO stars of the Globular Cluster 47 Tuc and test theories about Li variations among TO stars. method: We make use of high resolution (R~ 43000), high...
Na-O Anticorrelation and HB. II. The Na-O anticorrelation in the globular cluster NGC 6752 (2007)
Carretta, Eugenio, Bragaglia, Angela, Gratton, Raffaele, Lucatello, Sara, Momany, Yazan
We are studying the Na-O anticorrelation in several globular clusters of different Horizontal Branch (HB) morphology in order to derive a possible relation between (primordial) chemical...
Variations in the lithium abundances of turn off stars in the globular cluster 47 Tuc (2007)
Bonifacio, Piercarlo, Pasquini, Luca, Molaro, Paolo, Carretta, Eugenio, François, Patrick, G. Gratton, Raffaele, ...
aims: Our aim is to determine Li abundances in TO stars of the Globular Cluster 47 Tuc and test theories about Li variations among TO stars. method: We make use of high resolution (R~ 43000), high...
Variations in the lithium abundances of turn off stars in the globular cluster 47 Tuc (2007)
Bonifacio, Piercarlo, Pasquini, Luca, Molaro, Paolo, Carretta, Eugenio, François, Patrick, G. Gratton, Raffaele, ...
aims: Our aim is to determine Li abundances in TO stars of the Globular Cluster 47 Tuc and test theories about Li variations among TO stars. method: We make use of high resolution (R~ 43000), high...
On the Iron content of NGC 1978 in the LMC: a metal rich, chemically homogeneous cluster (2006)
Ferraro, Francesco R., Mucciarelli, Alessio, Carretta, Eugenio, Origlia, Livia
We present a detailed abundance analysis of giant stars in NGC 1978, a massive, intermediate-age stellar cluster in the Large Magellanic Cloud, characterized by a high ellipticity and suspected to...
The metallicity of the old open cluster NGC 6791 (2006)
Gratton, Raffaele, Bragaglia, Angela, Carretta, Eugenio, Tosi, Monica
We have observed four red clump stars in the very old and metal-rich open cluster NGC 6791 to derive its metallicity, using the high resolution spectrograph SARG mounted on the TNG. Using a spectrum...
Na-O Anticorrelation And HB I. The Na-O anticorrelation in NGC 2808 (2005)
Carretta, Eugenio, Bragaglia, Angela, Gratton, Raffaele, Leone, Francesco, Recio-Blanco, Alejandra, Lucatello, Sara
We derived atmospheric parameters and elemental abundances of Fe, O and Na for about 120 red giant stars in the Galactic globular cluster NGC 2808. Our results are based on the analysis of...
We present the abundance analysis of stars from the tip of the red giant branch (RGB) to below the RGB-bump in the globular cluster NGC 2808, based on high resolution echelle spectra. We derived...
Carretta, Eugenio, Bragaglia, Angela, Gratton, Raffaele, Tosi, Monica
We present the analysis of high resolution spectra of six red giant stars in the old open cluster Collinder 261. Reddening values for individual stars, derived from the relation between colours and...
The Binary Frequency Among Carbon-Enhanced, s-Process Rich, Metal-Poor Stars (2004)
Lucatello, Sara, Tsangarides, Stelios, Beers, Timothy C., Carretta, Eugenio, Gratton, Raffaele G., Ryan, Sean G.
We discuss radial velocities for a sample of carbon-enhanced, s-process rich, very metal-poor stars (CEMP-s hereafter), analyzed with high-resolution spectroscopy obtained over multiple epochs. We...
Observational evidence for a different IMF in the early Galaxy (2004)
Lucatello, Sara, Gratton, Raffaele G., Beers, Timothy C., Carretta, Eugenio
The unexpected high incidence of carbon-enhanced, s-process enriched unevolved stars amongst extremely metal-poor stars in the halo provides a significant constraint on the Initial Mass Function...
Carretta, Eugenio, Gratton, Raffaele, Lucatello, Sara, Bragaglia, Angela, Bonifacio, Piercarlo
Abundances of C and N are derived from features due to the CH G-band and to the UV CN band measured on high resolution (R ~ 40,000) UVES spectra of more than 40 dwarfs and subgiants in NGC 6397, NGC...
Star-to-star Na and O abundance variations along the red giant branch in NGC 2808 (2004)
Carretta, Eugenio, Bragaglia, Angela, Cacciari, Carla
We report for the first time Na and O abundances from high-resolution, high S/N echelle spectra of 20 red giants in NGC 2808, taken as part of the Science Verification program of the FLAMES...
Carretta, Eugenio, Gratton, Raffaele, Bragaglia, Angela, Bonifacio, Piercarlo, Pasquini, Luca
We used the UVES spectrograph on Kueyen (VLT UT2) to perform the abundance analysis of stars at the base of the giant branch (RGB) and at the main sequence turn-off in the globular cluster 47 Tuc...
Carretta, Eugenio, Bragaglia, Angela, Cacciari, Carla, Rossetti, Emanuel
We have used spectra obtained as part of the Science Verification program of the FLAMES multi-object spectrograph mounted on Kueyen (VLT-UT2) to perform an abundance analysis of stars along the giant...
Distances and ages of NGC 6397, NGC 6752 and 47 Tuc (2003)
Gratton, Raffaele, Bragaglia, Angela, Carretta, Eugenio, Clementini, Gisella, Desidera, Silvano, Grundahl, Frank, ...
Distances and absolute ages for the globular clusters NGC6397, NGC6752, and 47 Tuc are obtained using Main Sequence Fitting. Accurate reddenings and metal abundances (errors of 0.005 mag and 0.04...
Abundances for metal-poor stars with accurate parallaxes II. alpha-elements in the halo (2003)
Gratton, Raffaele, Carretta, Eugenio, Desidera, Silvano, Lucatello, Sara, Mazzei, Paola, Barbieri, Mauro
Abundances for alpha-elements and Fe in about 150 field subdwarfs and early subgiants with accurate parallaxes and kinematic data are used to discuss the run of abundance ratios in metal-poor stars...
Abundances for metal-poor stars with accurate parallaxes I. Basic data (2003)
Gratton, Raffaele, Carretta, Eugenio, Claudi, Riccardo, Lucatello, Sara, Barbieri, Mauro
We present element-to-element abundance ratios measured from high dispersion spectra for 150 field subdwarfs and early subgiants with accurate Hipparcos parallaxes (errors
Lucatello, Sara, Gratton, Raffaele, Cohen, Judith G., Beers, Timothy C., Christlieb, Norbert, Carretta, Eugenio, ...
We present a detailed abundance analysis, including spectral syntheses, of a very metal-poor ([Fe/H]= -2.7), peculiar main sequence star, HE0024-2523 detected during the course of the Keck Pilot...
Cohen, Judith G., Christlieb, Norbert, Beers, Timothy C., Gratton, Raffaele, Carretta, Eugenio
In this series of two papers we present a high dispersion spectroscopic analysis of 8 candidate extremely metal poor stars selected from the Hamburg/ESO Survey and of 6 additional very metal poor...
Carretta, Eugenio, Gratton, Raffaele, Cohen, Judith G., Beers, Timothy C., Christlieb, Norbert
We present a detailed abundance analysis of 8 stars selected as extremely metal poor candidates from the Hamburg/ESO Survey (HES). For comparison, we have also analysed 3 extremely metal-poor...
Carretta, Eugenio, Cohen, Judith G., Gratton, Raffaele G., Behr, Bradford B.
We present the results of the first analysis of high dispersion spectra of four red HB stars in the metal rich globular cluster NGC 6528, located in Baade's Window. We find that the mean [Fe/H] for...
Gratton, Raffaele, Carretta, Eugenio, Matteucci, Francesca, Sneden, Chris
The accurate O, Mg and Fe abundances derived in previous papers of this series from a homogenous reanalysis of high quality data for a large sample of stars are combined with stellar kinematics in...
Abundances of light elements in metal-poor stars. III. Data analysis and results (2000)
Carretta, Eugenio, Gratton, Raffaele, Sneden, Chris
We present the analysis of an extensive set of new and literature high quality data concerning Fe, C, N, O, Na, and Mg, exploiting the Teff scale determined in Gratton et al. (1996), and the non-LTE...
Carretta, Eugenio, Gratton, Raffaele, Clementini, Gisella
The discrepancy between a LONG distance scale derived from Hipparcos based distances to globular clusters via main sequence fitting to local subdwarfs, and a SHORT distance scale derived from the...
Gratton, Raffaele, Carretta, Eugenio, Matteucci, Francesca, Sneden, Chris
The accurate O, Mg and Fe abundances derived in previous papers of this series from a homogenous reanalysis of high quality data for a large sample of stars are combined with stellar kinematics in...
Mixing along the Red Giant Branch in Metal-poor Field Stars (1999)
Carretta, Eugenio, Gratton, Raffaele, Sneden, Chris, Bragaglia, Angela
We have determined Li, C, N, O, Na, and Fe abundances, and 12C/13C isotopic ratios for a sample of 62 field metal-poor stars (plus 43 taken from the literature). This large sample was used to show...
Cohen, Judith G., Gratton, Raffaele G., Behr, Bradford B., Carretta, Eugenio
We provide a high dispersion line-by-line abundance analysis of five red HB stars in the extremely metal rich galactic globular cluster NGC 6553. These red HB stars are significantly hotter than the...
Distances, ages, and epoch of formation of globular clusters (1999)
Carretta, Eugenio, Gratton, Raffaele, Clementini, Gisella, Pecci, Flavio Fusi
We review the results on distances and absolute ages of galactic globular clusters (GCs) obtained after the release of the Hipparcos catalogue. Several methods for the Population II local distance...
First Dredge-Up and further Mixing Mechanisms along the Red Giant Branch in Field Stars (1998)
Carretta, Eugenio, Gratton, Raffaele, Sneden, Chris, Bragaglia, Angela
In this research we use a large sample of field metal-poor stars ([Fe/H]
Carretta, Eugenio, Gratton, Raffaele G., Clementini, Gisella, Pecci, Flavio Fusi
We discuss the different biases affecting the sample of field subdwarfs selected from the Hipparcos Catalogue, and used in the Main Sequence Fitting technique to derive distances to Galactic Globular...
Carretta, Eugenio, Bragaglia, Angela
We present an improved calibration of photometric metallicity indicators, derived from the new metallicity scale for Globular Clusters presented by Carretta & Gratton (1997) and based on direct high...