Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: 51 Ophiuchus: A Possible Beta Pictoris Analog Measured with the Keck
  Interferometer Nuller
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg