相关论文: Stellar Nucleosynthesis in the Hyades Open Cluster

We present the homogeneous reanalysis of Mg and Al abundances from high resolution UVES/FLAMES spectra for 31 red giants in the globular cluster NGC 2808. We found a well defined Mg-Al anticorrelation reaching a regime of subsolar Mg…

We present the first chemical composition study of two unevolved stars in the globular cluster NGC 2808, obtained with the spectrograph X-shooter@VLT. NGC 2808 shows three discrete, well separated main sequences. The most accepted…

Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient, or when mass transfer in binary systems happens, chemically processed material is observed at the surface of O and B stars. ON stars…

We report the first high resolution, detailed abundances of 21 elements for giants in the Galactic bulge/bar within $1^\circ$ of the Galactic plane, where high extinction has rendered such studies challenging. Our high S/N and…

After few minutes the Universe evolved through conditions of temperature and density which permitted the first synthesis of astrophysically interesting abundances of D, 3He, 4He and 7Li. The relic abundances are sensitive probes of the…

Context. While most (if not all) Type I Galactic globular clusters (GGCs) are characterised by spreads in the abundances of light chemical elements (e.g. Li, N, O, Na, Mg, Al), it is not yet well established whether similar spreads may…

High spectral resolution and high signal-to-noise ratio optical spectra of red giants in the globular cluster Omega Centauri are analysed for stellar parameters and chemical abundances of 15 elements including helium by either line…

High resolution spectra (R > 40 000) for 9 main sequence turn-off stars and 9 subgiants in the globular cluster NGC 6752 were acquired with UVES on the VLT-Kueyen (UT2). These data have been used to determine the abundances of some heavy…

Abundances of 18 chemical elements have been derived for 11 A (normal and Am) and 11 F dwarfs members of the Coma Berenices open cluster in order to set constraints on evolutionary models including transport processes (radiative and…

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 ($-2 \lesssim \text{[Fe/H]} \lesssim -1$) subgiant stars in the solar neighborhood. Abundances are derived from…

This paper presents chemical abundances of twelve elements (C, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe) for 80 FGK dwarfs in the Pleiades open cluster, which span a temperature range of $\sim$2000 K in T$_{\rm eff}$, using the…

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…

We study the evolution, rotation, and surface abundances of O-type dwarfs in the Small Magellanic Cloud. We analyzed the UV and optical spectra of twenty-three objects and derived photospheric and wind properties. The observed binary…

We present the results of the first analysis of high dispersion spectra of four red HB stars in the metal rich globular cluster NGC 6528, located in Baade's Window. We find that the mean [Fe/H] for NGC 6528 is +0.07+-0.01 dex (error of the…

In this research we use a large sample of field metal-poor stars ([Fe/H]<-1) in different evolutionary phases to prove observationally that (small mass) subgiants (stars brighter than the first dredge-up and fainter than the RGB bump) have…

We present abundances of C, N, O, F, Na, and Fe in six giant stars of the tidally disrupted globular cluster NGC 6712. The abundances were derived by comparing synthetic spectra with high resolution infrared spectra obtained with the…

We obtain lithium abundances for G and K stars in Blanco 1, an open cluster with an age similar to, or slightly younger than, the Pleiades. We critically examine previous spectroscopic abundance analyses of Blanco 1 and conclude that while…

We have analyzed high-dispersion echelle spectra ($R \ga 50,000$) of red giant members for four open clusters to derive abundances for many elements. The spread in temperatures and gravities being very small among the red giants nearly the…

In order to provide a better basis for the study of mechanisms of nucleosynthesis of the light elements beyond hydrogen and helium in the oldest stars, the abundances of C, O, Mg, Si, P, S, K, and Ca have been derived from UV-HST and…

Stellar models for -2.5 <= [Fe/H] <= -0.5 that have been computed for variations in the C:N:O abundance ratio (for two different values of [CNO/Fe]) are compared with HST Wide Field Camera 3 (WFC3) observations of the globular clusters…