M 54 + Sagittarius = omega Centauri (2010)
Carretta, E., Bragaglia, A., Gratton, R. G., Lucatello, S., Bellazzini, M., Catanzaro, G., ...
We derive homogeneous abundances of Fe, O, Na and alpha-elements from high resolution FLAMES spectra for 76 red giant stars in NGC 6715 (M 54) and for 25 red giants in the surrounding nucleus of the...
Carretta, E., Bragaglia, A., Gratton, R. G., Lucatello, S., Catanzaro, G., Leone, F., ...
We present abundances of Fe, Na, and O for 1409 red giant stars in 15 galactic globular clusters, derived from the homogeneous analysis of high resolution FLAMES/GIRAFFE spectra. Combining the...
Villanova, S., Piotto, G., Gratton, R. G.
Helium has been proposed as the key element to interpret the observed multiple main sequences (MS), subgiant branches (SGB) and red giant branches (RGB), as well as the complex horizontal branch (HB)...
Beryllium abundances and star formation in the halo and in the thick disk (2009)
Smiljanic, R., Pasquini, L., Bonifacio, P., Galli, D., Gratton, R. G., Randich, S., ...
[abridged] Beryllium is a pure product of cosmic ray spallation. This implies a relatively simple evolution in time of the beryllium abundance and suggests its use as a time-like observable. We study...
S. Desidera, R. G. Gratton, M. Endl, M. Barbieri, R. U. Claudi, R. Cosentino, ...
(DOI: will be inserted by hand later) A search for planets in the metal-enriched binary HD 219542
Astronomy Astrophysics manuscript no. Gd052 May 4, 2004 (2007)
Doi Will Be, S. Desidera, R. G. Gratton, M. Endl, R. U. Claudi, R. Cosentino, ...
The star HD 219542B has been reported by us (Desidera et al. 2003) to show low-amplitude radial velocity variations that could be due to the presence of a Saturn-mass planetary companion or to...
A new search for planet transits in NGC 6791 (2007)
Montalto, M., Piotto, G., Desidera, S., De Marchi, F., Bruntt, H., Stetson, P. B., ...
Context. Searching for planets in open clusters allows us to study the effects of dynamical environment on planet formation and evolution. Aims. Considering the strong dependence of planet frequency...
Villanova, S., Piotto, G., King, I. R., Anderson, J., Bedin, L. R., Gratton, R. G., ...
We present metallicity measurements based on GIRAFFE@VLT spectra of 80 subgiant-branch stars of the Galactic globular cluster Omega Centauri. The VLT spectroscopic data are complemented by ACS/HST...
Carretta, E., Bragaglia, A., Gratton, R. G., Catanzaro, G., Leone, F., Sabbi, E., ...
We used the multifiber spectrograph FLAMES on the ESO Very Large Telescope UT2 to derive atmospheric parameters, metallicities and abundances of O and Na for 79 red giant stars in the Galactic...
Carretta, E., Bragaglia, A., Gratton, R. G., Momany, Y., Recio-Blanco, A., Cassisi, S., ...
We present the LTE abundance analysis of high resolution spectra for red giant stars in the peculiar bulge globular cluster NGC 6388. Spectra of seven members were taken using the UVES spectrograph...
Gratton, R. G., Lucatello, S., Bragaglia, A., Carretta, E., Cassisi, S., Momany, Y., ...
We present an analysis of FLAMES-Giraffe spectra for several bright giants in NGC 6441, to investigate the presence and extent of the Na-O anticorrelation in this anomalous globular cluster. The...
Detecting Extrasolar Planets with Integral Field Spectroscopy (2006)
Berton, A., Gratton, R. G., Feldt, M., Henning, T., Desidera, S., Turatto, M., ...
Observations of extrasolar planets using Integral Field Spectroscopy (IFS), if coupled with an extreme Adaptive Optics system and analyzed with a Simultaneous Differential Imaging technique (SDI),...
Na-O Anticorrelation And HB. III. The abundances of NGC 6441 from FLAMES-UVES spectra (2006)
Gratton, R. G., Lucatello, S., Bragaglia, A., Carretta, E., Momany, Y., Pancino, E., ...
The aim of the present work is to determine accurate metallicities for a group of red giant branch stars in the field of the bulge Globular Cluster NGC 6441. This is the third paper of a series...
Detecting extrasolar planets with integral field spectroscopy (2006)
Berton, A., Gratton, R. G., Feldt, M., Henning, Th., Desidera, S., Turatto, M., ...
Observations of extrasolar planets using integral field spectroscopy (IFS), if coupled with an extreme adaptive optics system and analyzed with a simultaneous differential imaging technique (SDI),...
Photometric and spectroscopic study of the intermediate age open cluster NGC 3960 (2005)
Bragaglia, A., Tosi, M., Carretta, E., Gratton, R. G., Marconi, G., Pompei, E.
We present CCD UBVI photometry and high-resolution spectroscopy of the intermediate age open cluster NGC 3960. The colour - magnitude diagrams (CMDs) derived from the photometric data and interpreted...
Line bisectors and radial velocity jitter from SARG spectra (2005)
Fiorenzano, A. F. Martinez, Gratton, R. G., Desidera, S., Cosentino, R., Endl, M.
We present an analysis of spectral line bisector variations for a few stars observed in the SARG high precision radial velocity planet survey, and discuss their relationship with differential radial...
Metal abundances of RR Lyrae stars in the metal rich globular cluster NGC 6441 (2005)
Clementini, G., Gratton, R. G., Bragaglia, A., Ripepi, V., Fiorenzano, A. F. Martinez, Held, E. V., ...
Low resolution spectra have been used to measure individual metal abundances of RR Lyrae stars in NGC 6441, a Galactic globular cluster known to have very unusual horizontal branch morphology and...
Sulphur abundance in Galactic stars (2005)
Caffau, E., Bonifacio, P., Faraggiana, R., Francois, P., Gratton, R. G., Barbieri, M.
We investigate sulphur abundance in 74 Galactic stars by using high resolution spectra obtained at ESO VLT and NTT telescopes. For the first time the abundances are derived, where possible, from...
Li in NGC 6752 and the formation of globular clusters (2005)
Pasquini, L., Bonifacio, P., Molaro, P., Francois, P., Spite, F., Gratton, R. G., ...
Li abundances for 9 Turnoff (TO) stars of the intermediate metallicity cluster ([Fe/H]=-1.4) NGC6752 are presented. The cluster is known to show abundance anomalies and anticorrelations observed in...
Clementini, G., Ripepi, V., Bragaglia, A., Fiorenzano, A. F. Martinez, Held, E. V., Gratton, R. G.
(abridged): Low resolution spectroscopy obtained with FORS2 at the Very Large Telescope (VLT) has been used to measure individual metal abundances ([Fe/H]) for 107 RR Lyrae stars, and trace the metal...
Early star formation in the Galaxy from beryllium and oxygen abundances (2005)
Pasquini, L., Galli, D., Gratton, R. G., Bonifacio, P., Randich, S., Valle, G.
We investigate the evolution of the star formation rate in the early Galaxy using beryllium and oxygen abundances in metal poor stars. Specifically, we show that stars belonging to two previously...
Precise reddening and metallicity of NGC6752 from FLAMES spectra (2005)
Gratton, R. G., Bragaglia, A., Carretta, E., De Angeli, F., Lucatello, S., Momany, Y., ...
(abridged) Accurate reddenings for Globular Clusters could be obtained by comparing the colour-temperature obtained using temperatures from reddening-free indicator (Halpha), with that given by...
Abundance anomalies in hot horizontal branch stars of the galactic globular cluster NGC 1904 (2005)
Fabbian, D., Recio-Blanco, A., Gratton, R. G., Piotto, G.
We present abundance measurements, based on high-resolution optical spectroscopic data obtained with the Ultraviolet and Visual Echelle Spectrograph mounted on Kueyen (Very Large Telescope UT2), for...
The Binary Frequency Among Carbon-enhanced, s-Process-rich, Metal-poor Stars (2005)
Lucatello, S., Tsangarides, S., Beers, T.C., Carretta, E., Gratton, R.G., Ryan, S.G.
Heavy elements and chemical enrichment in globular clusters (2004)
James, G., Francois, P., Bonifacio, P., Carretta, E., Gratton, R. G., Spite, F.
High resolution (R > 40 000) and high S/N spectra have been acquired with UVES on the VLT-Kueyen (Paranal Observatory, ESO Chile) for several main sequence turnoff stars (V ~ 17 mag) and subgiants at...
Pasquini, L., Bonifacio, P., Randich, S., Galli, D., Gratton, R. G.
We present the first detection of beryllium in two turnoff stars of the old, metal-poor globular cluster NGC 6397. The beryllium lines are clearly detected and we determine a mean beryllium abundance...
Metal abundances of RR Lyrae stars in the bar of the Large Magellanic Cloud (2004)
Gratton, R. G., Bragaglia, A., Clementini, G., Carretta, E., Di Fabrizio, L., Maio, M., ...
Metallicities ([Fe/H]) from low resolution spectroscopy obtained with the Very Large Telescope (VLT) are presented for 98 RR Lyrae and 3 short period Cepheids in the bar of the Large Magellanic...
No Planet Around HD 219542 B (2004)
Desidera, S., Gratton, R. G., Endl, M., Claudi, R. U., Cosentino, R., Barbieri, M., ...
The star HD 219542 B has been reported by us (Desidera et al. 2003) to show low-amplitude radial velocity variations that could be due to the presence of a Saturn-mass planetary companion or to...
Carretta, E., Bragaglia, A., Gratton, R. G., Tosi, M.
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...
Heavy elements abundances in turn-off stars and early subgiants in NGC 6752 (2003)
James, G., Francois, P., Bonifacio, P., Bragaglia, A., Carretta, E., Centurion, M., ...
High resolution spectra (R > 40 000) for 9 main sequence turn-off stars and 9 subgiants in the globular cluster NGC 6752 were acquired with UVES on the VLT-Kueyen (UT2). These data have been used to...
Mass motions and chromospheres of RGB stars in the globular cluster NGC 2808 (2003)
Cacciari, C., Bragaglia, A., Rossetti, E., Pecci, F. Fusi, Mulas, G., Carretta, E., ...
We present the results of the first observations, taken with FLAMES during Science Verification, of red giant branch (RGB) stars in the globular cluster NGC 2808. A total of 137 stars was observed,...
The chemical composition of the peculiar companion to the millisecond pulsar in NGC 6397 (2003)
Sabbi, E., Gratton, R. G., Bragaglia, A., Ferraro, F. R., Possenti, A., Camilo, F., ...
We present the chemical composition of the bright companion to the millisecond pulsar J1740-5340 in NGC 6397, based on high resolution spectra. Though the large rotation velocity of the star broadens...
A search for planets in the metal-enriched binary HD 219542 (2003)
Desidera, S., Gratton, R. G., Endl, M., Barbieri, M., Claudi, R. U., Cosentino, R., ...
The components of the wide binary HD 219542 were recently found to differ in metallicity by about 0.1 dex (Gratton et al. A&A 377, 123). In this paper, we present the results of 2 years of high...
The lithium content of the globular cluster NGC 6397 (2002)
Bonifacio, P., Pasquini, L., Spite, F., Bragaglia, A., Carretta, E., Castellani, V., ...
We make use of high resolution, high signal-to-noise ratio spectra of 12 turn-off stars in the metal-poor globular cluster NGC 6397 to measure its lithium content. We conclude that they all have the...
Galactic orbits of stars with planets (2001)
We have reconstructed the galactic orbits of the parent stars of exoplanets. For comparison, we have recalculated the galactic orbits of stars from the Edvardsson et al.(1993) catalog. A comparison...
CMD's, RR Lyrae's, clump stars and reddening in the LMC (2001)
Clementini, G., Bragaglia, A., Maio, M., Carretta, E., Gratton, R. G., Di Fabrizio, L.
We present new B, V, I photometry in the standard Johnson-Cousins photometric system of two regions near the bar of the Large Magellanic Cloud (LMC), one of which is very close to LMC field used for...
Metallicities for Double Mode RR Lyrae in the Large Magellanic Cloud (2001)
Bragaglia, A., Gratton, R. G., Carretta, E., Clementini, G., Di Fabrizio, L., Marconi, M.
Metallicities for six double mode RR Lyrae's (RRd's) in the Large Magellanic Cloud have been estimated using the DeltaS method. The derived [Fe/H] values are in the range [Fe/H] = -1.09 to -1.78 (or...
Discovery of a bipolar and highly variable mass outflow from the symbiotic binary StHa 190 (2001)
Munari, U., Tomov, T., Yudin, B. F., Marrese, P. M., Zwitter, T., Gratton, R. G., ...
A highly and rapidly variable bipolar mass outflow from StHa 190 has been discovered, the first time in a yellow symbiotic star. Permitted emission lines are flanked by symmetrical jet features and...
The O-Na and Mg-Al Anticorrelations in Turn-Off and early Subgiants in Globular Clusters (2000)
Gratton, R. G., Bonifacio, P., Bragaglia, A., Carretta, E., Castellani, V., Centurion, M., ...
High dispersion spectra (R>40,000) for a quite large number of stars at the main sequence turn-off and at the base of the subgiant branch in NGC6397 and NGC6752 were obtained with the UVES on Kueyen...
Metal Abundances of Red Clump Stars in Open Clusters: I. NGC 6819 (2000)
Bragaglia, A., Carretta, E., Gratton, R. G., Tosi, M., Bonanno, G., Bruno, P., ...
We present an analysis of high dispersion spectra (R~40000) of three red clump stars in the old open cluster NGC 6819. The spectra were obtained with SARG, the high dispersion spectrograph of the...
Distance to the Large Magellanic Cloud: the RR Lyrae stars (2000)
Clementini, G., Gratton, R. G., Bragaglia, A., Carretta, E., Di Fabrizio, L., Maio, M.
(abridged) New photometry and spectroscopy for more than a hundred RR Lyrae stars in two fields located close to the bar of the Large Magellanic Cloud (LMC) are used to derive new accurate estimates...
CU Comae: a new field double-mode RR Lyrae, the most metal poor discovered to date (2000)
Clementini, G., Di Tomaso, S., Di Fabrizio, L., Bragaglia, A., Merighi, R., Tosi, M., ...
We report the discovery of a new double-mode RR Lyrae variable (RRd) in the field of our Galaxy: CU Comae. CU Comae is the sixth such RRd identified to date and is the most metal-poor RRd ever...
Clementini, G., Bragaglia, A., Carretta, E., Di Fabrizio, L., Gratton, R. G.
The Large Magellanic Cloud (LMC) is widely considered a corner-stone of the astronomical distance scale, however a difference of 0.2-0.3 mag exists in its distance as predicted by the "short" and...
Homogeneous photometry and metal abundances for a large sample of Hipparcos metal-poor stars (1998)
Clementini, G., Gratton, R. G., Carretta, E., Sneden, C.
Homogeneous photometric data (Johnson V, B-V, V-K, Cousins V-I and Stromgren b-y), radial velocities, and abundances of Fe, O, Mg, Si, Ca, Ti, Cr and Ni are presented for 99 stars with high precision...
Distances and ages of globular clusters using Hipparcos parallaxes of local subdwarfs (1998)
Gratton, R. G., Carretta, E., Clementini, G.
We discuss the impact of Population II and Globular Cluster (GCs) stars on the derivation of the age of the Universe, and on the study of the formation and early evolution of galaxies, our own in...
Gratton, R. G., Pecci, F. Fusi, Carretta, E., Clementini, G., Corsi, C. E., Lattanzi, M. G.
High precision trigonometric parallaxes from the HIPPARCOS satellite and accurate metal abundances ([Fe/H], [O/Fe], and [alpha/Fe]) from high resolution spectroscopy for about 30 local subdwarfs have...
Metal Abundances of one Hundred Hipparcos Dwarfs (1997)
Gratton, R. G., Carretta, E., Clementini, G., Sneden, C.
Abundances for Fe, O, and the alpha-elements (Mg, Si, Ca, and Ti) have been derived from high resolution spectra of a sample of about one hundred dwarfs with high precision parallaxes measured by...
Ages of Globular Clusters from Hipparcos Parallaxes of Local Subdwarfs (1997)
Gratton, R. G., Pecci, F. Fusi, Carretta, E., Clementini, G., Corsi, C. E., Lattanzi, M. G.
We report here initial but still strongly conclusive results on absolute ages of galactic globular clusters (GGCs). This study is based on high precision trigonometric parallaxes from the HIPPARCOS...
Abundances for Globular Cluster Giants: I. Homogeneous Metallicities for 24 Clusters (1996)
We have obtained high-res, high S/N ratio CCD echelle spectra of 10 bright red giants in 3 GCs (47Tuc, NGC6752 and NGC6397) roughly spanning the range of metallicities of the galactic GC system; they...
Gratton, R. G., Carretta, E., Castelli, F.
We present atmospheric parameters for about 300 stars of different chemical composition, whose spectra will be used to study the galactic enrichment of Fe and light elements. These parameters were...
Metal Abundances Of One Hundred Hipparcos Dwarfs
R. G. Gratton, E. Carretta, G. Clementini, C. Sneden
Abundances for Fe, O, and the ff\Gammaelements (Mg, Si, Ca, and Ti) have been derived from high resolution spectra of a sample of about one hundred dwarfs with high precision parallaxes measured by...
R. G. Gratton, Gratton Fusi Pecci, G. Clementini, C. E. Corsi
High precision trigonometric parallaxes from the Hipparcos satellite and accurate metal abundances ([Fe/H], [O/Fe], and [ff/Fe]) from high resolution spectroscopy for about 30 local subdwarfs have...