Related papers: Abundance differences between components of wide b…
Parameters and abundances for 1002 stars of spectral types F, G, and K of luminosity class IV and V have been derived. After culling the sample for rotational velocity and effective temperature, 867 stars remain for discussion. Twenty-eight…
(Abridged) The abundance discrepancy problem in planetary nebulae (PNe) has long puzzled astronomers. NGC6153, with its high Abundance Discrepancy Factor (ADF~10), provides an opportunity to understand the chemical structure and ionisation…
High resolution, high S/N spectra have been obtained for a sample of 90 F and G main-sequence disk stars covering the metallicity range -1.0 < [Fe/H] < +0.1, and have been analysed in a parallel way to the work of Edvardsson et al. (1993).…
The origin of the abundance discrepancy is one of the key problems in the physics of photoionized nebula. In this work, we analize and discuss data for a sample of Galactic and extragalactic HII regions where this abundance discrepancy has…
We present the results of an abundance analysis of three G and two K dwarfs in the Praesepe open cluster based on high-resolution, moderate signal-to-noise-ratio spectra obtained with the ARC 3.5-m Telescope at Apache Point Observatory.…
The positive correlation between planet detection rate and host star iron abundance lends strong support to the core accretion theory of planet formation. However, iron is not the most significant mass contributor to the cores of giant…
Aims: We test the hypothesis that the pulsations in sdB stars are correlated with the surface abundances of iron-group elements. Any correlation might explain why, when given two spectroscopically similar stars, one will pulsate while the…
We study the stars of the binary system 16 Cygni to determine with high precision their chemical composition. Knowing that the component B has a detected planet of at least 1.5 Jupiter masses, we investigate if there are chemical…
We combine a catalog of wide binaries constructed from Gaia DR2 with [Fe/H] abundances from wide-field spectroscopic surveys to quantify how the binary fraction varies with metallicity over separations $50 \lesssim s/{\rm AU} \lesssim…
AR Aur A+B is a close binary of astrophysical interest, because dissimilar surface compositions are reported between similar late B-type dwarfs. A new spectroscopic study on this system was carried out based on the disentangled spectra, in…
NGC 362 is a non-common Type II Galactic globular cluster, showing a complex pseudo two-color diagram or 'chromosome map'. The clear separation of its stellar populations in the color-magnitude diagram and the distribution of the giant…
We present elemental abundances for all seven stars in Moving Group W11450 (Latham 1) to determine if they may be chemically related. These stars appear to be both spatially and kinematically related, but no spectroscopic abundance analysis…
[ABRIDGED] We report the results of a high-resolution spectroscopic survey of all the stars more luminous than Mv = 6.5 mag within 14.5 pc from the Sun. We derive stellar parameters and perform a preliminary abundance and kinematic analysis…
We present a study of the stellar parameters and iron abundances of 18 giant stars in 6 open clusters. The analysis was based on high-resolution and high-S/N spectra obtained with the UVES spectrograph (VLT-UT2). The results complement our…
To better characterize the abundance patterns produced by the r-process, we have derived new abundances or upper limits for the heavy elements zinc (Zn), yttrium (Y), lanthanum (La), europium (Eu), and lead (Pb). Our sample of 161…
We report abundance analysis for 30 M giant stars in two inner Galactic bulge fields at (l,b)=(0,-1.75) deg and at (l,b)=(1,-2.65) deg, based on R=25,000 infrared spectroscopy from 1.5-1.8um using NIRSPEC at the Keck II telescope. We find…
We conducted an analysis of the distribution of elements from lithium to europium in 200 dwarfs in the solar neighbourhood ~20 pc with temperatures in the range 4800-6200 K and metallicities [Fe/H] higher than -0.5 dex. Determinations of…
[Abridged] Deep optical observations of the spectra of 12 Galactic planetary nebulae (PNe) and 3 Magellanic Cloud PNe were presented in Paper I by Tsamis et al. (2003b), who carried out an abundance analysis using the collisionally excited…
This work presents a homogeneous determination of lithium abundances in a large sample of giant-planet hosting stars (N=117), and a control sample of disk stars without detected planets (N=145). The lithium abundances were derived using a…
Atmospheric parameters and chemical compositions for ten stars with metallicities in the region of -2.2< [Fe/H] <-0.6 were precisely determined using high resolution, high signal to noise, spectra. For each star the abundances, for 14 to 27…