K. Cunha, I. Hubeny, T. Lanz
We present non-LTE oxygen abundances for a sample of B stars in the Orion
association. The abundance calculations included non-LTE line formation and
used fully blanketed non-LTE model atmospheres. The stellar parameters were the
same as adopted in the previous study by Cunha & Lambert (1994). We find that
the young Orion stars in this sample of 10 stars are described by a single
oxygen abundance with an average value of A(O)=8.78 and a small dispersion of
+/- 0.05 dex, which is of the order of the uncertainties in the analysis. This
average oxygen abundance compares well with the average oxygen abundance
obtained previously in Cunha & Lambert (1994): A(O) = 8.72 +/- 0.13 although
this earlier study, based upon non-blanketed model atmospheres in LTE,
displayed larger scatter. Small scatter of chemical abundances in Orion B stars
had also been found in our previous studies for neon and argon; all based on
the same effective temperature scale. The derived oxygen abundance distribution
for the Orion association compares well with other results for the oxygen
abundance in the solar neighborhood.
View original:
http://arxiv.org/abs/1110.5879
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