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Related papers: Chemical compositions of semi-regular variable red…

200 papers

We have made observations with the Keck I telescope and HIRES at a resolution of $\sim$45,000 of five nearly identical stars at the turn-off of the metal-rich globular cluster M 71. Our mean Fe abundance, [Fe/H]=-0.80 +-0.02, is in…

Context: Globular clusters (GCs) in the outer halo are important probes of the composition and origin of the Galactic stellar halo. Aims: We derive chemical element abundance ratios in red giants belonging to the remote (R~90 kpc) GC Pal 3…

Astrophysics of Galaxies · Physics 2015-05-13 Andreas Koch , Patrick Côté , Andrew McWilliam

An extensive spectroscopic study was carried out for the beryllium abundances of 200 red giants (mostly of late G and early K type), which were determined from the near-UV Be II 3131.066 line based on high-dispersion spectra obtained by…

Solar and Stellar Astrophysics · Physics 2015-06-22 Yoichi Takeda , Akito Tajitsu

[Abridged abstract] We have performed an abundance analysis for 176 F- and G- dwarfs of the Galactic thick disk component. Using accurate radial velocities combined with $Hipparcos$ astrometry, kinematics (U, V, and W) and Galactic orbital…

Astrophysics · Physics 2009-11-13 Bacham E. Reddy , David L. Lambert , Carlos Allende Prieto

We present radial velocities and chemical abundances of O, Na, Mg, Al, Si, Ca, Cr, Fe, Co, Ni, and Cu for a sample of 156 red giant branch stars in two Galactic bulge fields centered near (l,b)=(+5.25,-3.02) and (0,-12). The (+5.25,-3.02)…

Solar and Stellar Astrophysics · Physics 2015-06-22 Christian I. Johnson , R. Michael Rich , Chiaki Kobayashi , Andrea Kunder , Andreas Koch

We present chemical abundances in a sample of luminous cool stars located within 30 pc of the Galactic Center. Abundances of carbon, nitrogen, oxygen, calcium, and iron were derived from high-resolution infrared spectra in the H- and…

Context. Globular clusters are known to host multiple stellar populations, which are a signature of their formation process. The globular cluster E3 is one of the few low-mass globulars that is thought not to host multiple populations.…

Solar and Stellar Astrophysics · Physics 2018-09-12 L. Monaco , S. Villanova , G. Carraro , A. Mucciarelli , C. Moni Bidin

This work explores the detailed chemistry of the Milky Way bulge using the HERMES spectrograph on the Anglo-Australian Telescope. Here we present the abundance ratios of 13 elements for 832 red giant branch and clump stars along the minor…

Astrophysics of Galaxies · Physics 2019-05-08 L. Duong , M. Asplund , D. M. Nataf , K. C. Freeman , M. Ness

High-resolution spectra of 13 core helium-burning stars in the thick disk of the Galaxy have been obtained with the SOFIN spectrograph on the Nordic Optical Telescope to investigate abundances of up to 22 chemical elements. Abundances of…

Astrophysics · Physics 2009-11-07 G. Tautvaisiene , B. Edvardsson , I. Tuominen , I. Ilyin

We have analysed high-dispersion echelle spectra ($R = 60000$) of red giant members of five open clusters to derive abundances for many elements from Na to Eu. The [Fe/H] values are $-0.06\pm0.03$ for Stock 2, $-0.11\pm0.03$ for NGC 2168,…

Solar and Stellar Astrophysics · Physics 2019-02-20 Arumalla B. S. Reddy , David L. Lambert

In this paper, we present low resolution (R=500) near-infrared spectra for selected and serendipitous sources in six inner in-plane Galactic fields, with the aim of analysing the stellar content present. From the equivalent widths of the…

Astrophysics · Physics 2009-11-13 C. González-Fernández , A. Cabrera-Lavers , P. L. Hammersley , F. Garzón

The physical structures of the outer atmospheres of red giants are not known. They are certainly complex and a range of recent observations are showing that we need to embrace to non-classical atmosphere models to interpret these regions.…

Galactic chemical evolution models which include sodium from type II supernovae alone underestimate the abundance of sodium in the interstellar medium by a factor of two to three over about 3 dex in metallicity and predict a flat behaviour…

Astrophysics · Physics 2007-05-23 Robert G. Izzard , Brad K. Gibson , Richard J. Stancliffe

With an aim to shed light on the origin of Li anomaly observed in a small fraction of red giants, we carried out a spectroscopic study on the observational characteristics of selected 20 bright Li-rich giants, in comparison with a large…

Solar and Stellar Astrophysics · Physics 2017-09-20 Yoichi Takeda , Akito Tajitsu

Elemental abundance ratios as tracers of stellar populations are discussed with emphasis on F, G, and K stars providing a `fossil' record of the chemical evolution of the Galaxy. Most abundance studies have been based on homogeneous 1D…

Astrophysics of Galaxies · Physics 2011-09-20 Poul Erik Nissen

We present model spectra of stellar populations with variable chemical composition. We derived the [alpha/Fe] abundance ratio of the stars of the most important libraries (ELODIE, CFLIB and MILES) using full spectrum fitting and we…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Philippe Prugniel , Mina Koleva

We measured $^{35}$Cl abundances in 52 M giants with metallicities between -0.5 $<$ [Fe/H] $<$ 0.12. Abundances and atmospheric parameters were derived using infrared spectra from CSHELL on the IRTF and from optical echelle spectra. We…

Solar and Stellar Astrophysics · Physics 2021-03-16 Z. G. Maas , C. A. Pilachowski

We performed a uniform and detailed abundance analysis of 12 refractory elements (Na, Mg, Al, Si, Ca, Ti, Cr, Ni, Co, Sc, Mn, and V) for a sample of 257 G- and K-type evolved stars from the CORALIE planet search program. To date, only one…

We present a detailed and uniform study of C, S, Zn and Cu abundances in a large set of planet host stars, as well as in a homogeneous comparison sample of solar-type dwarfs with no known planetary-mass companions. Carbon abundances were…

Astrophysics · Physics 2009-11-10 A. Ecuvillon , G. Israelian , N. C. Santos , M. Mayor , V. Villar , G. Bihain

In the search of a sample of metal-poor bright giants using Str{\"o}mgren photometry, we serendipitously found a sample of 26 young (ages younger than 1 Gyr) metal-rich giants, some of which have high rotational velocities.We determined the…