Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Absolute Proper Motions of Open Clusters: I. Observational data   Mean proper motions and parallaxes of 205 open clusters were determined from
their member stars found in the Hipparcos Catalogue. 360 clusters were searched
for possible members, excluding nearby clusters with distances D < 200 pc.
Members were selected using ground based information (photometry, radial
velocity, proper motion, distance from the cluster centre) and information
provided by Hipparcos (proper motion, parallax). Altogether 630 certain and 100
possible members were found. A comparison of the Hipparcos parallaxes with
photometric distances of open clusters shows good agreement. The Hipparcos data
confirm or reject the membership of several Cepheids in the studied clusters.

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The categories of this paper are: hep-th
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The categories of this paper are: cs
34
The categories of this paper are: chem-ph
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The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
18
The categories of this paper are: econ
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The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
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The categories of this paper are: patt-sol
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The categories of this paper are: cmp-lg
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The categories of this paper are: chao-dyn
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The categories of this paper are: math