Related papers: Abundances for metal-poor stars with accurate para…
We present chemical abundances of 57 metal-poor stars that are likely constituents of the outer stellar halo in the Milky Way. Almost all of the sample stars have an orbit reaching a maximum vertical distance (Z_max) of >5 kpc above and…
We present high-resolution Magellan/MIKE spectroscopy of the brightest star in the ultra-faint dwarf galaxy Leo IV. We measure an iron abundance of [Fe/H] = -3.2, adding to the rapidly growing sample of extremely metal-poor stars being…
We have determined Li abundances for eleven metal-poor turn-off stars, among which eight have [Fe/H]<-3, based on LTE analyses of high-resolution spectra obtained with the HDS on the Subaru telescope. The Li abundances for four of these…
High resolution UVES spectra of 40 main-sequence stars with -3.3 < [Fe/H] < -1.0 are used to derive S, Fe and Zn abundances from lines in the 400 - 950 nm region. For one star we also present novel observations of the SI triplet at 1.046…
Based on the second Gaia data release (DR2) and APOGEE (DR16) spectroscopic surveys, wedefined two kinds of star sample: high-velocity thick disk (HVTD) with $v{\phi}>90km/s$ and metal-richstellar halo (MRSH) with $v{\phi}<90km/s$. Due to…
Ground- and space-based observations of stellar heavy element abundances are providing a clearer picture of the chemical evolution of the Galaxy. A large number of (r)apid and (s)low neutron capture process elements, including the first…
We used moderately high-resolution, high S/N spectra to study the chemical composition of 10 field ab-type RR Lyrae stars. A new temperature scale was determined from literature Infrared Flux Method measures of subdwarfs and the Kurucz…
We present the determination of stellar parameters and individual elemental abundances for 6 million stars from $\sim$8 million low-resolution ($R\sim1800$) spectra from LAMOST DR5. This is based on a modeling approach that we dub $The$…
We present uniformly measured stellar metallicities for 463 stars in 13 Milky Way (MW) ultra-faint dwarf galaxies (UFDs; $M_V = -7.1$ to $-0.8$) using narrowband CaHK (F395N) imaging taken with the Hubble Space Telescope (HST). This…
Results from high-resolution spectral analyses of a selected sample of CH stars are presented. Detailed chemical composition studies of these objects, which could reveal abundance patterns that in turn provide information regarding…
ABRIDGED: METHODS: We have conducted a high-resolution spectroscopic study of 714 F and G dwarf and subgiant stars in the Solar neighbourhood. The star sample has been kinematically selected to trace the Galactic thin and thick disks to…
We report the first survey of chemical abundances in M and K dwarf stars using atomic absorption lines in high resolution spectra. We have measured Fe and Ti abundances in 35 M and K dwarf stars using equivalent widths measured from (lambda…
Neutral Fe lines in metal-poor stars yield conflicting abundances depending on whether and how deviations from local thermodynamic equilibrium (LTE) are considered. We have collected new high resolution and high signal-to-noise ultraviolet…
We report the detection of an Al II line at 2669.155 Angstroms in 11 metal-poor stars, using ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. We derive Al abundances from this…
The most metal-poor stars are the relics of the early chemical evolution of the Galaxy. Their chemical composition is an important tool to constrain the nucleosynthesis in the first generation of stars. The aim is to observe a sample of…
Accurate stellar parameters and precise elemental abundances are vital pieces to correctly characterize discovered planetary systems, better understand planet formation, and trace galactic chemical evolution. We have performed a uniform…
Precise abundances of 18 elements have been derived for ten stars known to host giant planets from high signal-to-noise ratio, high-resolution echelle spectroscopy. Internal uncertainties in the derived abundances are typically <=0.05 dex.…
From an initial sample of a few hundred stars selected for an Hipparcos program, a subsample of 33 objects with direct determination of their effective temperature, bolometric magnitude and [Fe/H] has been derived. An accurate observational…
We present vanadium (V) abundances for 255 metal-poor stars, derived from high-resolution optical spectra from the Magellan Inamori Kyocera Echelle spectrograph on the Magellan Telescopes at Las Campanas Observatory, the Robert G. Tull…
We present a method to determine nitrogen abundance ratios with respect to iron ([N/Fe]) from molecular CN-band features observed in low-resolution ($R \sim$ 2000) stellar spectra obtained by the Sloan Digital Sky Survey (SDSS) and the…