Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High Resolution Optical Spectroscopy of a Newly Discovered Post-AGB Star
  with a Surprising Metallicity in the Globular Cluster M79   An abundance analysis based on a high-resolution spectrum is presented for a
newly discovered post-AGB star in the globular cluster M79. The surprising
result is that the iron abundance of the star is apparently about 0.6 dex less
than that of the cluster's red giants as reported by published studies
including a recent high-resolution spectroscopic analysis by Carretta and
colleagues. Abundances relative to iron appear to be the same for the post-AGB
star and the red giants for the 15 common elements. It is suggested that the
explanation for the lower abundances of the post-AGB star may be that its
atmospheric structure differs from that of a classical atmosphere; the
temperature gradient may be flatter than predicted by a classical atmosphere.

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The categories of this paper are: math-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
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The categories of this paper are: patt-sol
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The categories of this paper are: supr-con
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The categories of this paper are: q-bio
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The categories of this paper are: cond-mat
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The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: stat
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The categories of this paper are: q-alg