Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Light pollution at high zenith angles, as measured at Cerro Tololo
  Inter-American Observatory
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
2
The categories of this paper are: math
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex