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Related papers: NGC 362: another globular cluster with a split red…

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We performed low-resolution spectroscopy for the red giant branch stars in an intriguing globular cluster (GC) NGC 2808, which hosts subpopulations with extreme helium and light-element abundances. In order to trace N, C, and Ca abundance…

Astrophysics of Galaxies · Physics 2021-09-08 Seungsoo Hong , Dongwook Lim , Chul Chung , Jaeyeon Kim , Sang-Il Han , Young-Wook Lee

We present aluminium abundances for a sample of about 100 red giant stars in each of the Galactic globular clusters 47 Tuc (NGC 104) and M 4 (NGC 6121). We have derived homogeneous abundances from intermediate-resolution FLAMES/GIRAFFE…

Astrophysics of Galaxies · Physics 2015-06-12 Eugenio Carretta , Raffaele Gratton , Angela Bragaglia , Valentina D'Orazi , Sara Lucatello

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 used the Ultraviolet Imaging Telescope during the March 1995 Astro-2 mission to obtain a deep far-UV image of the globular cluster NGC 362, which was formerly thought to have an almost entirely red horizontal branch (HB). 84 hot (T_eff >…

We present the abundances analysis for a sample of 11 red giant branch stars in the metal-poor globular cluster NGC 6809 based on high-resolution spectra. Our main goals are to characterize its chemical composition and analyze this…

Solar and Stellar Astrophysics · Physics 2018-12-19 M. J. Rain , S. Villanova , C. Muñoz , C. Valenzuela-Calderon

We present Hubble Space Telescope (HST) photometric results for NGC 6402, a highly reddened very luminous Galactic globular cluster (GC). Recent spectroscopic observations of its red giant stars have shown a quite peculiar behavior in the…

We present detailed chemical compositions of 10 red giant star members of the Galactic (open) cluster NGC 752, derived from high-resolution (R $\approx$ 60,000), high signal-to-noise ($S/N$ $\geq$ 140) spectra. We confirmed cluster…

Solar and Stellar Astrophysics · Physics 2015-06-23 G. Böcek Topcu , M. Afşar , M. Schaeuble , C. Sneden

We modify our combined ("deep mixing" plus "primordial") scenario explaining the star-to-star abundance variations in globular cluster red giants in such a way that it confirms with new experimental data: (i) the new and better constrained…

Astrophysics · Physics 2009-11-06 Pavel A. Denissenkov , Achim Weiss

We have observed ten red giant stars in four old Large Magellanic Cloud globular clusters with the high-resolution spectrograph MIKE on the Magellan Landon Clay 6.5-m telescope. The stars in our sample have up to 20 elemental abundance…

Astrophysics · Physics 2009-11-13 Jennifer A. Johnson , Inese I. Ivans , Peter B. Stetson

It is very likely that most (perhaps all) Galactic globular clusters (GGCs) have experienced two or even more star-formation episodes. This is indicated, in particular, by peculiar chemical composition of the cluster stars which show large…

Solar and Stellar Astrophysics · Physics 2014-02-18 A. Černiauskas , A. Kučinskas , P. Bonifacio , S. M. Andrievsky , S. A. Korotin , V. Dobrovolskas

We have observed 15 red giant stars in the relatively massive, metal-poor globular cluster NGC 4833 using the Magellan Inamori Kyocera Echelle spectrograph at Magellan. We calculate stellar parameters for each star and perform a standard…

Solar and Stellar Astrophysics · Physics 2015-06-24 Ian U. Roederer , Ian B. Thompson

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

We present the abundance analysis for a sample of 7 red giant branch stars in the metal-poor globular cluster NGC 4372 based on UVES spectra acquired as part of the Gaia-ESO Survey. This is the first extensive study of this cluster from…

We investigate the massive star content of NGC 3603, the closest known giant H II region. We have obtained spectra of 26 stars in the central cluster using the Baade 6.5-m telescope (Magellan I). Of these 26 stars, 16 had no previous…

Astrophysics · Physics 2009-11-13 Nicholas W. Melena , Philip Massey , Nidia I. Morrell , Amanda M. Zangari

Several recent studies have reported the detection of an anomalous color spread along the red giant branch (RGB) of some globular clusters (GC) that appears only when color indices including a near ultraviolet band (such as Johnson U or…

Astrophysics of Galaxies · Physics 2015-05-20 C. Lardo , M. Bellazzini , E. Pancino , E. Carretta , A. Bragaglia , E. Dalessandro

We have serendipitously identified the first lithium-rich giant star located close to the red giant branch bump in a globular cluster. Through intermediate-resolution FLAMES spectra we derived a lithium abundance of A(Li)=2.55 (assuming…

We present radial velocities and chemical abundances for red giant branch stars in the Galactic bulge globular clusters NGC 6342 and NGC 6366. The velocities and abundances are based on measurements of high resolution (R > 20,000) spectra…

Solar and Stellar Astrophysics · Physics 2016-07-06 Christian I. Johnson , Nelson Caldwell , R. Michael Rich , Catherine A. Pilachowski , Tiffany Hsyu

The field of the globular cluster NGC 362 was monitored between 1997 and 2015 in a search for variable stars. BV light curves were obtained for 151 periodic or likely periodic variables, over a hundred of which are new detections. Twelve…

Solar and Stellar Astrophysics · Physics 2016-10-21 M. Rozyczka , I. B. Thompson , W. Narloch , W. Pych , A. Schwarzenberg - Czerny

We present CH and CN index analysis and C and N abundance calculations based on the low-resolution blue spectra of red giant branch (RGB) stars in the Galactic globular cluster NGC 7089 (M 2). Our main goal is to investigate the C-N…

Solar and Stellar Astrophysics · Physics 2015-06-11 C. Lardo , E. Pancino , A Mucciarelli , A. P. Milone

[Abridged] In recent years the view of Galactic globular clusters as simple stellar populations has changed dramatically, as it is now thought that basically all GCs host multiple stellar populations, each with its own chemical abundance…

Solar and Stellar Astrophysics · Physics 2014-11-19 Santi Cassisi , Maurizio Salaris , Adriano Pietrinferni , Jorick S. Vink , Matteo Monelli
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