Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: C/O Ratios of Stars with Transiting Hot Jupiter Exoplanets   The relative abundances of carbon and oxygen have long been recognized as
fundamental diagnostics of stellar chemical evolution. Now, the growing number
of exoplanet observations enable estimation of these elements in exoplanetary
atmospheres. In hot Jupiters, the C/O ratio affects the partitioning of carbon
in the major observable molecules, making these elements diagnostic of
temperature structure and composition. Here we present measurements of carbon
and oxygen abundances in 16 stars that host transiting hot Jupiter exoplanets,
and compare our C/O ratios to those measured in larger samples of host stars,
as well as those estimated for the corresponding exoplanet atmospheres. With
standard stellar abundance analysis we derive stellar parameters as well as
[C/H] and [O/H] from multiple abundance indicators, including synthesis fitting
of the [O I] 6300 {\AA} line and NLTE corrections for the O I triplet. Our
results, in agreement with recent suggestions, indicate that
previously-measured exoplanet host star C/O ratios may have been overestimated.
The mean transiting exoplanet host star C/O ratio from this sample is 0.54
(C/O$_{solar}$=0.54), versus previously-measured C/O$_{host~star}$ means of
$\sim$0.65-0.75. We also observe the increase in C/O with [Fe/H] expected for
all stars based on Galactic chemical evolution; a linear fit to our results
falls slightly below that of other exoplanet host stars studies but has a
similar slope. Though the C/O ratios of even the most-observed exoplanets are
still uncertain, the more precise abundance analysis possible right now for
their host stars can help constrain these planets' formation environments and
current compositions.

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The categories of this paper are: nucl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: acc-phys
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: math-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: hep-th
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The categories of this paper are: adap-org
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The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
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The categories of this paper are: solv-int
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The categories of this paper are: q-fin