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Related papers: Metallicity variations in the Type II globular clu…

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We present the high resolution (R $\approx$ 60000), high signal-to-noise (S/N $\simeq$ 120) spectroscopic analysis of 12 red giant members of the Galactic open cluster NGC 6940. We applied Yonsei-Yale isochrones to the color-magnitude…

Solar and Stellar Astrophysics · Physics 2019-03-12 G. Böcek Topcu , M. Afşar , C. Sneden

Variations in chemical abundances with evolutionary phase have been identified among stars in globular and open clusters with a wide range of metallicities. In the metal-poor clusters, these variations compare well with predictions from…

Solar and Stellar Astrophysics · Physics 2023-12-18 T. Nordlander , P. Gruyters , O. Richard , A. J. Korn

Our FLAMES survey of Na-O anticorrelation in globular clusters (GCs) is extended to NGC 4833, a metal-poor GC with a long blue tail on the horizontal branch (HB). We present the abundance analysis for a large sample of 78 red giants based…

Astrophysics of Galaxies · Physics 2015-06-18 E. Carretta , A. Bragaglia , R. G. Gratton , V. D'Orazi , S. Lucatello , Y. Momany , A. Sollima , M. Bellazzini , G. Catanzaro , F. Leone

NGC 6388 is one of the most massive Galactic globular clusters (GC) and it is an old, metal-rich, Galactic bulge cluster. By exploiting previous spectroscopic observations we were able to bypass the uncertainties in membership related to…

Solar and Stellar Astrophysics · Physics 2022-03-16 Eugenio Carretta , Angela Bragaglia

Assuming that in the atmospheres of low-mass, metal-poor red giant stars, 1-D models based on LTE accurately predict the abundance of iron from Fe II, we derive a globular cluster metallicity scale based on the equivalent widths of Fe II…

Astrophysics · Physics 2009-07-28 Robert P. Kraft , Inese I. Ivans

We present the abundance analysis of a sample of more than 120 red giants in the globular cluster (GC) NGC 1851, based on FLAMES spectra. We find a small but detectable metallicity spread. This spread is compatible with the presence of two…

We report the abundance analysis of one red giant branch star in the metal-poor outer halo globular cluster NGC 5694. We obtain [Fe/H] = -1.93, based on the ionized lines, and our metallicity measurement is in good agreement with previous…

Astrophysics · Physics 2009-11-11 Jae-Woo Lee , Mercedes Lopez-Morales , Bruce W. Carney

Abundance variations in moderately metal-rich globular clusters can give clues about the formation and chemical enrichment of globular clusters. CN, CH, Na, Mg and Al indices in spectra of 89 stars of the template metal-rich globular…

Astrophysics · Physics 2009-11-13 A. Alves-Brito , R. P. Schiavon , B. Castilho , B. Barbuy

We have performed a detailed spectral analysis of the inner halo Galactic globular cluster (GC) NGC 6723 using high resolution (R$\approx$ 22000-48000) spectra for for eleven red giant branch stars collected with MIKE (Magellan) and FEROS…

Solar and Stellar Astrophysics · Physics 2019-07-10 Juliana Crestani , Alan Alves-Brito , Giuseppe Bono , Arthur A. Puls , Javier Alonso-García

We present the first results of a detailed abundance analysis, based on VLT observations, of giant stars in the very metal-rich globular cluster NGC 6528. We will be able to tie the horizontal branch abundances (see e.g. Carretta et al.…

Astrophysics · Physics 2007-05-23 Sofia Feltzing , Francesca Primas , Rachel Johnson

The spectroscopic and photometric signals of the star-to-star abundance variations found in globular clusters seem to be correlated with global parameters like the cluster's metallicity, mass and age. Understanding this behaviour could…

Recent observations have shown that a growing number of the most massive Galactic globular clusters contain multiple populations of stars with different [Fe/H] and neutron-capture element abundances. NGC 6273 has only recently been…

There is increasing evidence for the presence of multiple red giant branches (RGBs) in the color-magnitude diagrams of massive globular clusters (GCs). In order to investigate the origin of this split on the RGB, we have performed new…

NGC 6522 is a moderately metal-poor bulge globular cluster ([Fe/H]$\sim$$-$1.0), and it is a well-studied representative among a number of moderately metal-poor blue horizontal branch clusters located in the bulge. The NGC 6522 abundance…

The HST UV Survey of Globular Clusters (GCs) has investigated GCs and their stellar populations. In previous papers of this series we have introduced a pseudo two-color diagram, "chromosome map" (ChM), that maximises the separation between…

Solar and Stellar Astrophysics · Physics 2019-05-29 A. F. Marino , A. P. Milone , A. Renzini , F. D'Antona , J. Anderson , L. R. Bedin , A. Bellini , G. Cordoni , E. P. Lagioia , G. Piotto , M. Tailo

We present the homogeneous reanalysis of Mg and Al abundances from high resolution UVES/FLAMES spectra for 31 red giants in the globular cluster NGC 2808. We found a well defined Mg-Al anticorrelation reaching a regime of subsolar Mg…

Solar and Stellar Astrophysics · Physics 2015-06-23 Eugenio Carretta

We have studied the chemical composition of NGC 1806, a massive, intermediate-age globular cluster that shows a double main sequence turnoff. We analyzed a sample of high-resolution spectra (secured with FLAMES at the Very Large Telescope)…

Solar and Stellar Astrophysics · Physics 2015-06-22 A. Mucciarelli , E. Dalessandro , F. R. Ferraro , L. Origlia , B. Lanzoni

We present the first high spectral resolution abundance analysis of two newly discovered Galactic globular clusters, namely Mercer 5 and 2MASS GC02 residing in regions of high interstellar reddening in the direction of the Galactic center.…

Solar and Stellar Astrophysics · Physics 2015-06-23 Francisco Penaloza , Peter Pessev , Sergio Vasquez , Jura Borissova , Radostin Kurtev , Manuela Zoccali

The globular cluster M 2 has a photometrically detected double red giant branch (RGB) sequence. We investigate here the chemical differences between the two RGBs in order to gain insight in the star formation history of this cluster. The…

Solar and Stellar Astrophysics · Physics 2015-06-15 C. Lardo , E. Pancino , A. Mucciarelli , M. Bellazzini , M. Rejkuba , S. Marinoni , G. Cocozza , G. Altavilla , S. Ragaini

AIMS. We present abundance analysis based on high resolution spectra of 105 isolated red giant branch (RGB) stars in the Galactic Globular Cluster NGC 6121 (M4). Our aim is to study its star population in the context of the multi-population…

Astrophysics · Physics 2009-11-13 A. F. Marino , S. Villanova , G. Piotto , A. P. Milone , Y. Momany , L. R. Bedin , A. M. Medling