Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: GD 99 - an unusual, rarely observed DAV white dwarf   New observations of GD 99 are analysed. The unusual pulsation behaviour,
showing both long and short periods, has been confirmed. All the available
periods show a grouping of short and long period modes with roughly regular
spacing. If we interpret the groups separately, a binary nature can be a
possible explanation as in the similar cases of WD 2350-0054 and G29-38.

12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga