338 datasets found

I explore the effects of observational errors on nebular chemical abundances using a sample of 179 optical spectra of 42 planetary nebulae (PNe) observed by different authors....

We make use of APOGEE and Gaia data to identify stars that are consistent with being born in the same association or star cluster as the Sun. We limit our analysis to stars that...

Extremely metal-poor (EMP) stars are old objects that mostly formed very early after the big bang. They are rare and, to select them, we have to rely on low-resolution...

We study the M-type asymptotic giant branch (AGB) population of the Large Magellanic Cloud (LMC) by characterizing the individual sources in terms of the main properties of the...

Study of primary stars lying in Sirius-like systems with various masses of white dwarf (WD) companions and orbital separations is one of the key aspects to understand the origin...

We investigate NLTE effects for magnesium and calcium in the atmospheres of late-type giant and supergiant stars. The aim of this paper is to provide a grid of NLTE/LTE...

We present stellar parameters and abundances of 13 elements for 18 very metal-poor (VMP; [Fe/H]{<}-2.0) stars, selected as extremely metal-poor (EMP; [Fe/H]{<}-3.0)...

We construct a sample of 644 carbon-enhanced metal-poor (CEMP) stars with abundance analyses based on moderate- to high-resolution spectroscopic studies. Dynamical parameters...

We measure abundances of 12 elements (Na, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni) in a sample of 86 metal-poor (-2<~[Fe/H]<~-1) subgiant stars in the solar...

We report on the discovery of five carbon-enhanced metal-poor (CEMP) stars in the metallicity range of -3.3<[Fe/H]{<}-2.4. These stars were selected from the LAMOST DR3...

We report the discovery of RAVE J203843.2-002333, a bright (V=12.73), very metal-poor ([Fe/H]=-2.91), r-process-enhanced ([Eu/Fe]=+1.64 and [Ba/Eu]=-0.81) star selected from the...

We present chemical abundance measurements of two metal-poor red giant stars in the ultra-faint dwarf galaxy Bootes I, based on Magellan/MIKE high-resolution spectra. For...

The carbon-enhanced metal-poor star BD+44{deg}493 ([Fe/H]=-3.9) has been proposed as a candidate second-generation star enriched by metals from a single Pop III star. We report...

We present a homogeneous chemical abundance analysis of five of the most metal-poor stars in the Sculptor dwarf spheroidal galaxy. We analyze new and archival high resolution...

We report on early results from a pilot program searching for metal-poor stars with LAMOST and follow-up high-resolution observation acquired with the MIKE spectrograph attached...

We examine the metallicity distribution function (MDF) and fraction of carbon-enhanced metal-poor (CEMP) stars in a sample that includes 86 stars with [Fe/H]<=-3.0, based on...

We present a homogeneous chemical abundance analysis of 16 elements in 190 metal-poor Galactic halo stars (38 program and 152 literature objects). The sample includes 171 stars...

We report the discovery of 34 stars in the Hamburg/ESO Survey (HES) for metal-poor stars and the Sloan Digital Sky Survey (SDSS) that have [Fe/H]<~-3.0. Their median and...

We present an analysis of three years of precision radial velocity (RV) measurements of 160 metal-poor stars observed with HIRES on the Keck 1 telescope. We report on...

The chemical compositions of 26 metal-poor stars that exhibit strong CH and/or C2 molecular bands are determined. Twenty-two stars in our sample satisfy our definition for...