Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Will Gravitational Waves Discover the First Extra-Galactic Planetary
  System?   Gravitational waves have opened a new observational window through which some
of the most exotic objects in the Universe, as well as some of the secrets of
gravitation itself, can now be revealed. Among all these new discoveries, we
recently demonstrated [N. Tamanini & C. Danielski, Nat. Astron., 3(9), 858
(2019)] that space-based gravitational wave observations will have the
potential to detect a new population of massive circumbinary exoplanets
everywhere inside our Galaxy. In this essay we argue that these circumbinary
planetary systems can also be detected outside the Milky Way, in particular
within its satellite galaxies. Space-based gravitational wave observations
might thus constitute the mean to detect the first extra-galactic planetary
system, a target beyond the reach of standard electromagnetic searches.

36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol