Astron. Astrophys. Suppl. Ser. 144, 203-209
A. Hui-Bon-Hoa
Send offprint request: A. Hui-Bon-Hoa
1 - Laboratoire d'Astrophysique Extragalactique et de Cosmologie, CNRS (UMR 8631),
Observatoire de Paris, Université Paris 7, DAEC, Observatoire de Meudon, F-92195 Meudon
Cedex, France
2 - Département de physique, Université de Moncton, Moncton, N.-B., E1A 3E9, Canada
Received April 12, 1999; accepted February 25, 2000
Detailed abundances of 9 field A and Am stars are derived for Mg, Ca, Sc, Cr, Fe, and Ni
using high resolution spectroscopy. Most of our sample Am stars show the characteristic
deficiencies of Ca and Sc on one hand, and the overabundances of the iron peak elements on
the other, which is consistent with the predictions of the diffusion model for Main Sequence
or slightly evolved stars. There seems to be a correlation between abundances of Ca and Sc
and the effective temperature for stars of similar age: the abundance of Ca increases with
increasing mass whereas that of Sc decreases. Two of our Am stars have a different abundance
pattern: Ca is overabundant in the hot magnetic Am star o Peg and its abundance is nearly
normal in the metallic giant star Pup. The other objects of our sample have globally
a solar composition except 28 And, which shows significant deficiencies for most the studied
elements.
Key words: stars: abundances; chemically peculiar
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