Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First detection of a gravitational microlensing candidate towards the
  Small Magellanic Cloud   We report the first discovery of a gravitational microlensing candidate
towards a new population of source stars, the Small Magellanic Cloud (SMC). The
candidate event's light curve shows no variation for 3 years before an upward
excursion lasting $ \sim 217$ days that peaks around January 11, 1997 at a
magnification of $ \sim 2.1$. Microlensing events towards the Large Magellanic
Cloud and the Galactic bulge have allowed important conclusions to be reached
on the stellar and dark matter content of the Milky Way. The SMC gives a new
line-of-sight through the Milky Way, and is expected to prove useful in
determining the flattening of the Galactic halo.

9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex