Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The Second Stellar Spectrum and the non-LTE Problem of the Second Kind
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con