Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Planets in Stellar Clusters Extensive Search. V. Search for planets and
  identification of 18 new variable stars in the old open cluster NGC 188   We have undertaken a long-term project, Planets in Stellar Clusters Extensive
Search (PISCES), to search for transiting planets in open clusters. In this
paper we present the results for NGC 188, an old, rather populous cluster. We
have monitored the cluster for more than 87 hours, spread over 45 nights. We
have not detected any good transiting planet candidates. We have discovered 18
new variable stars in the cluster, bringing the total number of identified
variables to 46, and present for them high precision light curves, spanning 15
months.

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The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
0
The categories of this paper are: hep-ph
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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: chao-dyn
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The categories of this paper are: q-fin
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The categories of this paper are: q-alg
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The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org
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The categories of this paper are: chem-ph
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The categories of this paper are: eess