相关论文: Abundances and physical parameters for stars in th…

We present a study of accurate stellar parameters and iron abundances for 39 giants and 16 dwarfs in the 13 open clusters IC2714, IC4651, IC4756, NGC2360, NGC2423, NGC2447 (M93), NGC2539, NGC2682 (M67), NGC3114, NGC3680, NGC4349, NGC5822,…

Context: Homogeneous investigations of red giant stars in open clusters contribute to studies of internal evolutionary mixing processes inside stars, which are reflected in abundances of mixing-sensitive chemical elements like carbon,…

We have obtained the first high resolution spectra of individual stars in the dwarf irregular galaxy, NGC 6822. The spectra of the two A-type supergiants were obtained at the VLT and Keck Observatories, using UVES and HIRES, respectively. A…

The chemical composition of stars in open clusters provides the best information on the chemical evolution of stars via comparison of the main sequence stars with the evolved giants. This is a case study of the abundances in the dwarfs and…

We present a chemical abundance study of giant stars in the Galactic open cluster NGC 5822, which hosts two barium stars (#002 and #201) and three lithium-enriched giants (#006, #102, and #240). Using high-resolution optical and…

This is the first of a series of papers devoted to derive the metallicity of old open clusters in order to study the time evolution of the chemical abundance gradient in the Galactic disk. We present detailed iron abundances from high…

We report a detailed spectroscopic abundance analysis for a sample of 18 F-K dwarfs of the young open cluster IC 4665. Stellar parameters and element abundances of Li, O, Mg, Si, Ca, Ti, Cr, Fe and Ni have been derived using the…

Chemical abundances of about fifteen elements from oxygen to europium are measured in seven red giants of the two open clusters NGC 2360 and NGC 2447. The effective temperatures of the giants are determined spectroscopically by taking…

We present an analysis of high-resolution spectra of three core-helium-burning "clump" stars and two first ascent giants in the open cluster IC 4651. Atmospheric parameters (T_eff, log_g, v_t, and [Fe/H]) were determined in our previous…

We present a chemical composition analysis of 36 giant stars in the mildly metal-poor globular cluster M5 (NGC 5904). The analysis makes use of high resolution data acquired at the Keck I telescope as well as a re-analysis of high…

We present a detailed chemical analysis of 22 stars along the colour-magnitude sequence of the intermediate-age (1.7 Gyr) open cluster IC 4651. We find for the cluster a well-defined Fe abundance of [Fe/H]= 0.10 +/- 0.03 (internal errors),…

Sulfur and zinc are chemically volatile elements, which play significant roles as depletion-free tracers in studying galactic chemical evolution. However, regarding red giants having evolved off the main sequence, reliable abundance…

We report abundance analysis for 6 M giant members of the old open cluster NGC6791, based on infrared spectroscopy (1.5-1.8 micron) at R=25,000, using the NIRSPEC spectrograph at the Keck II telescope. We find the iron abundance <[Fe/H]>=…

We present detailed elemental abundances of 12 subgiants in the open cluster IC 4756 including Na, Al, Mg, Si, Ca, Ti, Cr, Ni, Fe, Zn and Ba. We measure the cluster to have [Fe/H] = -0.01 +/- 0.10. Most of the measured star-to-star [X/H]…

CONTEXT:The detailed chemical abundances of extremely metal-poor (EMP) stars are key guides to understanding the early chemical evolution of the Galaxy. Most existing data are, however, for giant stars which may have experienced internal…

We present atmospheric parameters and iron abundances derived from high-resolution spectra for three samples of dwarf stars: stars which are known to host close-in giant planets (CGP), stars for which radial velocity data exclude the…

We present a new version of the compiled catalogue of nearby stars for which was published the spectoscopically determined effective temperatures, surface gravities, and abundances of iron, magnesium, calcium, silicon, and titanium.…

We have observed 15 red giant stars in the relatively massive, metal-poor globular cluster NGC 4833 using the Magellan Inamori Kyocera Echelle spectrograph at Magellan. We calculate stellar parameters for each star and perform a standard…

We present the first results of a detailed abundance analysis, based on VLT observations, of giant stars in the very metal-rich globular cluster NGC 6528. We will be able to tie the horizontal branch abundances (see e.g. Carretta et al.…

We present a homogeneous photometric and spectroscopic analysis of 18 stars along the evolutionary sequence of the metal-poor globular cluster NGC 6397 ([Fe/H] = -2), from the main-sequence turnoff point to red giants below the bump. The…