Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Physical characteristics and non-keplerian orbital motion of "propeller"
  moons embedded in Saturn's rings   We report the discovery of several large "propeller" moons in the outer part
of Saturn's A ring, objects large enough to be followed over the 5-year
duration of the Cassini mission. These are the first objects ever discovered
that can be tracked as individual moons, but do not orbit in empty space. We
infer sizes up to 1--2 km for the unseen moonlets at the center of the
propeller-shaped structures, though many structural and photometric properties
of propeller structures remain unclear. Finally, we demonstrate that some
propellers undergo sustained non-keplerian orbit motion. (Note: This arXiv
version of the paper contains supplementary tables that were left out of the
ApJL version due to lack of space).

11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics