Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectral atlas of A-type supergiants   Based on high-spectral-resolution observations (R=60000) performed with the
6-m BTA telescope in combination with the echelle spectrograph NES, we have
studied the optical spectra of three A-type supergiants: a peculiar supergiant
3 Pup, a post-AGB star BD+48 1220, and a massive $\alpha$ Cyg, which belong to
essentially different stages of evolution. A spectral atlas for these stars is
prepared in the wavelength interval of 3920 to 6720 \AA.

18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
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The categories of this paper are: q-fin
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The categories of this paper are: alg-geom
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
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The categories of this paper are: hep-lat
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The categories of this paper are: math-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an