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Milky Way globular clusters (GCs) display chemical enrichment in a phenomenon called multiple stellar populations (MSPs). While the enrichment mechanism is not fully understood, there is a correlation between a cluster's mass and the…

The study of the Milky Way stellar discs in the context of galaxy formation is discussed. In particular we explore the properties of the Milky Way disc using a new sample of about 550 dwarf stars for which we have recently obtained…

Astrophysics · Physics 2009-11-13 S. Feltzing , T. Bensby

Low mass stars (< 2-2.5 M_sun) exhibit, at all the stages of their evolution, signatures of processes that require challenging modeling beyond the standard stellar theory. In this paper we focus on their peculiarities while they climb the…

Astrophysics · Physics 2016-08-30 Corinne Charbonnel , Ana Palacios

All globular clusters (GCs) studied to date show evidence for internal variation in their light element abundances. These variations have been interpreted as evidence for multiple star formation episodes within GCs, with secondary episodes…

Astrophysics of Galaxies · Physics 2015-05-27 Charlie Conroy

Studies during the last decade have revealed that nearly all Globular Clusters (GCs) host multiple populations (MPs) of stars with a distinctive chemical patterns in light elements. No evidence of such MPs has been found so far in…

Astrophysics of Galaxies · Physics 2016-05-25 I. Cabrera-Ziri , C. Lardo , B. Davies , N. Bastian , G. Beccari , S. S. Larsen , S. Hernandez

We discuss oxygen and iron abundance patterns in K and M red-giant members of the Galactic bulge and in the young and massive M-type stars inhabiting the very center of the Milky Way. The abundance results from the different bulge studies…

Astrophysics · Physics 2009-11-13 K. Cunha , V. Smith , K. Sellgren , R. Blum , S. Ramirez , D. Terndrup

The Galactic Centre (GC) has experienced a high degree of recent star-forming activity, as evidenced by the large number of massive stars currently residing there. The relative abundances of chemical elements in the GC may provide insights…

We have previously analysed the spectra of 135 early B-type stars in the LMC and found several groups of stars that have chemical compositions that conflict with the theory of rotational mixing. Here we extend this study to Galactic and SMC…

Solar and Stellar Astrophysics · Physics 2009-11-13 I. Hunter , I. Brott , N. Langer , D. J. Lennon , P. L. Dufton , I. D. Howarth , R. S. I. Ryans , C. Trundle , C. J. Evans , A. de Koter , S. J. Smartt

Almost several decades after the discovery of the first multiple populations in galactic globular clusters (GC) the debate on their formation is still extremely current and NGC2808 remains one of the best benchmark to test any scenario for…

Solar and Stellar Astrophysics · Physics 2018-07-18 Marcella Di Criscienzo , Paolo Ventura , Francesca D'Antona , Flavia Dell'Agli , Marco Tailo

We present a critical analysis of the nature of the so-called Li-rich RGB stars. For a majority of the stars, we have used Hipparcos parallaxes to determine masses and evolutionary states by comparing their position on the…

Astrophysics · Physics 2007-05-23 Corinne Charbonnel , Suchitra C. Balachandran

Young alpha-rich (YAR) stars have been detected in the past as outliers to the local age $\rm-$ [$\alpha$/Fe] relation. These objects are enhanced in $\alpha$-elements but apparently younger than typical thick disc stars. We study the…

Astrophysics of Galaxies · Physics 2023-08-23 Valeria Cerqui , Misha Haywood , Paola Di Matteo , David Katz , Frédéric Royer

In this paper we study the underlying stellar population of a sample of 65 nearby early-type galaxies predominantly located in low density environments. Ages, metallicities and [alpha/Fe] ratios have been derived through the comparison of…

Astrophysics · Physics 2010-10-28 F. Annibali , A. Bressan , R. Rampazzo , W. W. Zeilinger , L. Danese

A significant fraction of stars in globular clusters (about 70%-85%) exhibit peculiar chemical patterns with strong abundance variations in light elements along with constant abundances in heavy elements. These abundance anomalies can be…

Astrophysics · Physics 2015-05-13 T. Decressin , H. Baumgardt , P. Kroupa , G. Meynet , C. Charbonnel

Recent observations demonstrate that the thin and thick disks of the Galaxy have different chemical abundance trends and evolution timescales. The relative abundances of $\alpha$-elements in the thick Galactic disk are increased relative to…

Astrophysics · Physics 2009-11-11 T. V. Nykytyuk , T. V. Mishenina

High-resolution, high signal-to-noise spectral data are presented for four young B-type stars lying towards the Galactic Centre. Determination of their atmospheric parameters from their absorption line profiles, and uvby photometric…

Astrophysics · Physics 2009-10-31 S. J. Smartt , K. A. Venn , P. L. Dufton , D. J. Lennon , W. R. J. Rolleston , F. P. Keenan

Red giants are increasingly used as stellar population tracers due to their well-understood evolution and the availability of asteroseismic observables. However, stellar binarity can alter observable properties and introduce strong biases.…

Solar and Stellar Astrophysics · Physics 2026-02-02 Paul G. Beck

Drawing from the LEGA-C dataset, we present the spectroscopic view of the stellar population across a large volume- and mass-selected sample of galaxies at large lookback time. We measure the 4000\AA\ break (D$_n$4000) and Balmer absorption…

This is a brief overview of the elemental abundance patterns that have been observed in the different Galactic stellar populations. Main focus is on studies that are based on high-resolution spectra of dwarf and subgiant stars, and in some…

Astrophysics of Galaxies · Physics 2013-12-18 Thomas Bensby

We conducted an investigation on the chemical abundances of 4,316 stars in the red giant branch (RGB) phase from the recently released APO-K2 catalogue. Our aim was to characterize the abundance trends of the single elements with…

Astrophysics of Galaxies · Physics 2024-07-09 G. Valle , M. Dell'Omodarme , P. G. Prada Moroni , S. Degl'Innocenti

The evolution of galaxies is imprinted in their stellar populations. Several stellar population properties in massive early-type galaxies have been shown to correlate with intrinsic galaxy properties like the galaxy's central velocity…

Astrophysics of Galaxies · Physics 2021-12-22 A. Feldmeier-Krause , I. Lonoce , W. L. Freedman