Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Formation and Evolution of Planetary Systems (FEPS): Discovery of an
  Unusual Debris System Associated with HD 12039   We report the discovery of a debris system associated with the $\sim 30$ Myr
old G3/5V star HD 12039 using {\it Spitzer Space Telescope} observations from
3.6 -- 160$\mu$m. An observed infrared excess (L$_{\rm IR}$/L$_{\ast} =
1\times10^{-4}$) above the expected photosphere for $\lambda \gtrsim 14\mu$m is
fit by thermally emitting material with a color temperature of T$\sim 110$ K,
warmer than the majority of debris disks identified to date around Sun-like
stars. The object is not detected at 70$\mu$m with a 3$\sigma$ upper limit 6
times the expected photospheric flux. The spectrum of the infrared excess can
be explained by warm, optically thin material comprised of blackbody-like
grains of size $\gtrsim 7 \mu$m that reside in a belt orbiting the star at 4--6
AU. An alternate model dominated by smaller grains, near the blow-out size
$a\sim 0.5\mu$m, located at 30-40AU is also possible, but requires the dust to
have been produced recently since such small grains will be expelled from the
system by radiation pressure in $\sim$ few $\times 10^{2}$yrs.

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The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
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The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an