Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Hamburg/ESO R-process Enhanced Star survey (HERES) VIII. The r+s
  star HE 1405 0822   Aims.The aim of this study is a detailed abundance analysis of the newly
discovered r-rich star HE 1405 0822, which has [Fe=H]=-2.40. This star shows
enhancements of both r- and s-elements, [Ba/Fe]= +1.95 and [Eu/Fe]=1.54, for
which reason it is called r+s star. Methods.Stellar parameters and element
abundances were determined by analying high-quality VLT/UVES spectra. We used
Fe I line excitation equilibria to derive the effective temperature. The
surface gravity was calculated from the Fei/Feii and Ti I/Ti II equilibria.
Results.We determined accurate abundances for 39 elements, including 19
neutron-capture elements. HE 1405-0822 is a red giant. Its strong enhancements
of C, N, and s-elements are the consequence of enrichment by a former AGB
companion with an initial mass of less than 3 M_Sun. The heavy n-capture
element abundances (including Eu, Yb, and Hf) seen in HE 1405-0822 do not agree
with the r-process pattern seen in strongly r-process-enhanced stars. We
discuss possible enrichment scenarios for this star. The enhanced alpha
elements can be explained as the result of enrichment by supernovae of type II.
Na and Mg may have partly been synthesized in a former AGB companion, when the
primary 22^Ne acted as a neutron poison in the 13^C-pocket.

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The categories of this paper are: ao-sci
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The categories of this paper are: math
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The categories of this paper are: econ
33
The categories of this paper are: plasm-ph
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The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
7
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: hep-lat
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The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
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The categories of this paper are: cs
37
The categories of this paper are: supr-con