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We evaluate non-local thermodynamical equilibrium (non-LTE) line formation for neutral sodium in model atmospheres of the 79 red giants using the model atom that incorporates the best available atomic data. The non-LTE abundances of Na were…

Solar and Stellar Astrophysics · Physics 2015-06-22 S. A. Alexeeva , Yu. V. Pakhomov , L. I. Mashonkina

We study the distribution of aluminum abundances among red giants in the peculiar globular cluster NGC 1851. Aluminum abundances were derived from the strong doublet Al I 8772-8773 A measured on intermediate resolution FLAMES spectra of 50…

Astrophysics of Galaxies · Physics 2015-06-05 Eugenio Carretta , Valentina D'Orazi , Raffaele G. Gratton , Sara Lucatello

One of the high-level goals of Galactic archaeology is chemical tagging of stars across the Milky Way to piece together its assembly history. For this to work, stars born together must be uniquely chemically homogeneous. Wide binary systems…

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 stars and their link with global cluster…

Astrophysics · Physics 2008-11-24 Eugenio Carretta , Angela Bragaglia , Raffaele G. Gratton , Sara Lucatello

The aim of this paper is to provide the fundamental parameters and abundances for a large sample of local clump giants with a high accuracy. The selection of clump stars for the sample group was made applying a color - absolute magnitude…

We present the chemical abundance analysis of 33 red giant stars belonging to the complex stellar system Terzan 5. We confirm the discovery of two stellar populations (Ferraro et al. 2009, Nature, 462,483) with distinct iron abundances: a…

Astrophysics of Galaxies · Physics 2015-05-20 L. Origlia , R. M. Rich , F. R. Ferraro , B. Lanzoni , M. Bellazzini , E. Dalessandro , A. Mucciarelli , E. Valenti , G. Beccari

Detailed chemical composition of stars is of prime interest for a range of topics in modern stellar astrophysics, such as the chemical evolution of the Galaxy or the formation, composition, and structure of exoplanets. In this work, we…

Solar and Stellar Astrophysics · Physics 2024-01-18 C. Duque-Arribas , H. M. Tabernero , D. Montes , J. A. Caballero

Multiple stellar populations in the Milky Way globular clusters manifest themselves with a large variety. Although chemical abundance variations in light elements, including He, are ubiquitous, the amount of these variations is different in…

Solar and Stellar Astrophysics · Physics 2015-11-03 Anna Fabiola Marino

According to previous spectral analyses of Wolf-Rayet type central stars, late [WC] subtypes show systematically higher carbon-to-helium abundance ratios than early [WC] subtypes. If this were true, it would rule out that these stars form…

Astrophysics · Physics 2009-06-25 H. Todt , G. Gräfener , W. -R. Hamann

Cool red giants and supergiants are among the most complex and fascinating stars in the Universe. They are bright and large, and thus can be observed to enormous distances allowing us to study the properties of their host galaxies, such as…

Solar and Stellar Astrophysics · Physics 2016-07-27 Maria Bergemann , Rolf-Peter Kudritzki , Ben Davies

A small fraction of red giants are known to be lithium (Li) rich, in contradiction with expectations from stellar evolutionary theory. A possible explanation for these atypical giants is the engulfment of a Li-rich planet or brown dwarf by…

Solar and Stellar Astrophysics · Physics 2016-10-05 Claudia Aguilera-Gómez , Julio Chanamé , Marc Pinsonneault , Joleen Carlberg

Context: Open clusters are very useful targets for examining possible trends in galactocentric distance and age, especially when young and old open clusters are compared. Aims: We carried out a detailed spectroscopic analysis to derive the…

Solar and Stellar Astrophysics · Physics 2015-06-15 O. J. Katime Santrich , C. B. Pereira , N. A. Drake

We present an abundance analysis of seven super-star clusters in the disk of M83. The near-infrared spectra of these clusters are dominated by Red Supergiants, and the spectral similarity in the J-band of such stars at uniform metallicity…

We present a chemical abundance distribution study in 14 $\alpha$, odd-Z, even-Z, light, and Fe-peak elements of approximately 3200 intermediate metallicity giant stars from the APOGEE survey. The main aim of our analysis is to explore the…

Astrophysics of Galaxies · Physics 2016-03-02 Keith Hawkins , Paula Jofre , Thomas Masseron , Gerry Gilmore

Context: Chemical element abundances for distant Galactic globular clusters (GCs) hold important clues to the origin of the Milky Way halo and its substructures. Aims: We study the chemical composition of red giant stars in Pal 4 - one of…

Astrophysics of Galaxies · Physics 2015-05-18 Andreas Koch , Patrick Côté

The chemical abundance patterns of gas and stars in galaxies are powerful probes of galaxies' star formation histories and the astrophysics of galaxy assembly but are challenging to measure with confidence in distant galaxies. In this…

Astrophysics of Galaxies · Physics 2022-02-09 Allison L. Strom , Gwen C. Rudie , Charles C. Steidel , Ryan F. Trainor

We have investigated the abundance of several chemical elements in two large stellar samples kinematically representative of the thin and the thick disks of the Galaxy. Chemical, kinematical and age data have been collected from high…

Astrophysics · Physics 2007-05-23 Pascal Girard , Caroline Soubiran

Context: Lithium is a fragile element, which is easily destroyed in the stellar interior. The existence of lithium-rich giants still represents a challenge for stellar evolution models. Aims: We have collected a large database of…

Solar and Stellar Astrophysics · Physics 2015-05-27 L. Monaco , S. Villanova , C. Moni Bidin , G. Carraro , D. Geisler , P. Bonifacio , O. A. Gonzalez , M. Zoccali , L. Jilkova

The latest Gaia Focused Product Release (FPR) provided variability information for $\sim$1000 long-period red giant binaries, the largest sample to date of this binary type having both photometric and spectroscopic time series observations.…

Solar and Stellar Astrophysics · Physics 2025-04-09 Camila Navarrete , Alejandra Recio-Blanco , Patrick de Laverny , Ana Escorza

Intermediate resolution spectra at the Ca II triplet have been obtained for 55 candidate red giants in the field of the globular cluster M22 with the VLT/FORS instrument. Spectra were also obtained for a number of red giants in standard…

Astrophysics of Galaxies · Physics 2014-11-20 G. S. Da Costa , E. V. Held , I. Saviane , M. Gullieuszik
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