Bibcode
DOI
Cavallo, Robert M.; Pilachowski, Catherine A.; Rebolo, R.
Bibliographical reference
Publications of the Astronomical Society of the Pacific, v.109, p.226-235
Advertised on:
3
1997
Citations
66
Refereed citations
55
Description
This paper examines the oxygen abundance of 24 main-sequence turn-off
and subgiant stars through the permitted O I triplet near $lambda$7774
{AA}. In agreement with prior investigators, we find that the O
abundance from the triplet is about 0.53 dex higher than is typically
found from other means such as the [O I] $lambda$6300 {AA} line or the
UV and IR bands from OH. Our average [O/Fe] is +0.79 $pm$ 0.29 (1
$sigma$), with the uncertainties in the individual methods being
dominated by systematic errors in our incomplete understanding of the
formation of these high excitation lines under non-LTE conditions.
Several methods of resolving the on-going discrepancy are discussed in
detail. We find that the problem is not fixed by simply changing the
model atmosphere parameters, and that the best methods seem to require a
detailed non-LTE analysis based on both the structure of the oxygen atom
and the source function within and above the photosphere. The trend of
increasing O with decreasing Fe is briefly explored and is found to be
qualitatively consistent with other works. (SECTION: Stars)