Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The low density transiting exoplanet WASP-15b   We report the discovery of a low-density exoplanet transiting an 11th
magnitude star in the Southern hemisphere. WASP-15b, which orbits its host star
with a period P=3.7520656+-0.0000028d has a mass M_p=0.542+-0.050M_J and radius
R_p=1.428+-0.077R_J, and is therefore the one of least dense transiting
exoplanets so far discovered (rho_p=0.247+-0.035g cm^-3). An analysis of the
spectrum of the host star shows it to be of spectral type around F5, with an
effective temperature T_eff=6300+-100K and [Fe/H]=-0.17+-0.11.

24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ