Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A new method for unveiling Open Clusters in Gaia: new nearby Open
  Clusters confirmed by DR2
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics