Cool Stars 14 - Submitted Abstract # 35
This version created on 05 October 2006

Pinning Down the Solar Neon Abundance using non-LTE Results from Orion
B stars


Katia Cunha, NOAO
Ivan Hubeny, University of Arizona
Thierry Lanz, University of Maryland

We present results from non-LTE neon abundance calculations for a
sample of B stars in the Orion association.  The neon abundances were
derived by means of non-LTE model atmospheres which are fully
blanketed and by adopting an extensive neon model atom constructed
with updated atomic data.  Our calculations show that the non-LTE
treatment results in a much lower neon abundances when compared to the
simplified LTE values;  the non-LTE results being lower by roughly 0.5
dex than the LTE.  In addition, we find that the young Orion stars
show a very homogeneous neon abundance distribution with an average
neon that is higher by roughly 0.3 dex than the most recent assessment
of the solar abundance.  We discuss B-star abundance results for other
light elements, such as C,N,O,Mg and S available in the literature and
compare with the solar abundances in order to argue that the derived
neon abudances for the Orion B-star sample are a good representation
of the solar neighbourhood neon abundance.  We argue that the Orion
abundance of A(Ne)=8.1 should represent a reliable indirect estimate
of the solar neon abundance value.

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