1997/10/28 by S. Feltzing, Sofia Feltzing, B. Gustafsson +1 · 5 citations
Physics and Astronomy · #Abundance (ecology) #Astronomical and nuclear sciences #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Biology #Circumbinary planet #Ecology #K-type main-sequence star #Materials science #Metal #Metallurgy #Photometry (optics) #Physics #Population #Stars #Stellar, planetary, and galactic studies #Supernova #T Tauri star #astro-ph
paper · pdf · doi:10.1051/aas:1998400
Accepted for publication in Astronomy and Astrophysics Supplement Series. RGO preprint No. 284
arxiv created 1997/10/28 · openalex publication_date 1998/04/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We have derived elemental abundances of O, Na, Mg, Al, Si, Ca, Ti, Cr, Mn, Fe, Co, Ni 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 few Extreme Pop I stars were included in the latter sample. The stars have -0.1<Fe/H]<0.42 dex. We find that the elemental abundances of Mg, Al, Si, Ca, Ti, Cr and Ni all follow [Fe/H]. Our data put further constraints on models of galactic chemical evolution, in particular of Cr, Mn and Co which has not previously been studied for dwarf stars with [Me/H]>0.1 dex. The increase in [Na/Fe] and [Al/Fe] as a function of [Fe/H] found previously by Edvardsson et al. (1993a) has been confirmed for [Na/Fe]. This upturning relation, and the scatter around it, are shown not to be due to a mixture of populations with different mean distances to the galactic centre. We have not been able to trace any tendency for relative abundances of O, Si, and Ti relative to Fe to vary with the stellar velocities, i.e. the stars present mean distance to the galactic centre. These results imply that there is no significant difference in the chemical evolution of the different stellar populations for stars with [Me/H]>0.1 dex. SMR stars on highly eccentric orbits, alleged to trace the evolution of the chemical evolution in the galactic Bulge, have previously been found overabundant in O, Mg and Si. We have included 3 such stars from the study by Barbuy & Grenon (1990). We find them to be less metal rich and the other elemental abundances remain puzzling. Our study includes 5 K dwarf stars and reveal a striking example of overionization.