منابع مشابه
Abundances in stars with exoplanets
Extensive spectroscopic studies of stars with and without planets have concluded that stars hosting planets are significantly more metal-rich than those without planets. More subtle trends of different chemical elements begin to appear as the number of detected extrasolar planetary systems continues to grow. I review our current knowledge concerning the observed abundance trends of various chem...
متن کاملAbundances in Metal-rich Stars ?
We have derived elemental abundances of O, Ni as well as for a number of s-elements for 47 G and K dwarf, with Me/H]> 0:1 dex. The selection of stars was based on their kinematics as well as on their uvby ?-photometry. One sample of stars on rather eccentric orbits traces the chemical evolution interior to the solar orbit and another, on circular orbits, the evolution around the solar orbit. A ...
متن کاملElemental Abundances in PG 1159 Stars
The hydrogen-deficiency in extremely hot post-AGB stars of spectral class PG1159 is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse that consumes the hydrogen envelope, exposing the usuallyhidden intershell region. Thus, the photospheric elemental abundances of these stars allow to draw conclusions about details of nuclear burning and mixing processes in the pre...
متن کاملSulphur and iron abundances in halo stars
From equivalent widths of the S i lines at 8694 Å, Israelian & Rebolo (2001) and Takada-Hidai et al. (2002) have derived a surprisingly high sulphur-to-iron ratio ([S/Fe] ≃ 0.5 to 0.7) in six halo stars with [Fe/H] ≃ −2.0 suggesting perhaps that hypernovae made a significant contribution to the formation of elements in the early Galaxy. To investigate this problem we have used high-resolution s...
متن کاملSulphur abundances in metal - poor stars ⋆
We investigate the debated “sulphur discrepancy” found among metal-poor stars of the Galactic halo with [Fe/H]<−2. This discrepancy stems in part from the use of two different sets of sulphur lines, the very weak triplet at 8694 95 Å and the stronger triplet lines at 9212 9238 Å. For three representative cases of metal-poor dwarf, turnoff and subgiant stars, we argue that the abundances from th...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2005
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921305006319