منابع مشابه
Chemical abundances in cool metal rich disk dwarf stars
The present study of spectra of twelve metal-rich cool dwarf stars, carefully selected in order to cover a range of temperatures (∼ 4400 − 6000 K), is a follow up on Feltzing & Gustafsson (1998) with the aim to understand the apparent over-ionization and anomalous elemental abundances found by them for the K dwarf stars in their sample. Our method of analysis employs synthetic spectra of the fu...
متن کاملSpectroscopic Abundances in Cool Pleiades Dwarfs and Ngc 2264 Stars
We derive parameters and abundances of several elements in two cool Pleiades dwarfs, four cool NGC 2264 preÈmain-sequence stars, and a probable NGC 2264 nonmember from high-resolution, moderate signal-to-noise ratio, Keck/HIRES spectra. Our Pleiades Fe abundance agrees with previous spectroscopic and photometric values of hotter stars and does not resolve the 0.3 mag distance modulus discrepanc...
متن کاملDust production and mass loss in cool evolved stars
Following the red giant branch phase and the subsequent core He-burning phase, the lowto intermediate-mass stars (0.8 < M/M < 8) begin to ascend the asymptotic giant branch (AGB). Pulsations levitate material from the stellar surface and provide density enhancements and shocks, which can encourage dust formation and re-processing. The dust composition depends on the atmospheric chemistry (abund...
متن کاملLithium abundances from the 6104 Å line in cool Pleiades stars
Lithium abundances determined by spectral synthesis from both the 6708 Å resonance line and the 6104 Å subordinate line are reported for 11 Pleiades late-G and early-K stars observed at the William Herschel Telescope. Firm detections of the weak subordinate line are found for four objects, marginal detections for four, and upper limits for the remaining three stars. Some of these spectra were p...
متن کاملBarium abundances in cool dwarf stars as a constraint to s- and r-process nucleosynthesis
We revise barium abundances in 11 cool stars with metallicities ranging from −2.65 to 0.05. The results are based on differential NLTE model atmosphere analyses of spectra that have a typical S/N of 200 and a resolution of 40000 or 60000. To minimize systematic errors of theoretical modeling and to be sure that elemental surface abundances are not contaminated by thermonuclear reaction products...
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ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 1988
ISSN: 0252-9211
DOI: 10.1017/s0252921100093350