Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The age of old Magelanic Cloud clusters. I: NGC 2257.   Deep CCD photometry down to V=24.5 is presented for the old Magellanic
Globular cluster NGC 2257. The main result cna be summarized as follows: i) the
RGB Bump has been detected at V=18.7+-0.1, and is compatible with determination
of this feature in GGCs; ii) NGC 2257 seems to be 2-3 Gyrs younger than a
typical GGC; iii) the helium abundance has been estimated to be Y=0.21+-0.03,
using the R- method as calibrated by Buzzoni et al., 1983.

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The categories of this paper are: atom-ph
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph