Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discovery of a Thorne-Zytkow object candidate in the Small Magellanic
  Cloud   Thorne-Zytkow objects (TZOs) are a theoretical class of star in which a
compact neutron star is surrounded by a large, diffuse envelope. Supergiant
TZOs are predicted to be almost identical in appearance to red supergiants
(RSGs). The best features that can be used at present to distinguish TZOs from
the general RSG population are the unusually strong heavy-element and Li lines
present in their spectra, products of the star's fully convective envelope
linking the photosphere with the extraordinarily hot burning region in the
vicinity of the neutron star core. Here we present our discovery of a TZO
candidate in the Small Magellanic Cloud. It is the first star to display the
distinctive chemical profile of anomalous element enhancements thought to be
unique to TZOs. The positive detection of a TZO will provide the first direct
evidence for a completely new model of stellar interiors, a theoretically
predicted fate for massive binary systems, and never-before-seen
nucleosynthesis processes that would offer a new channel for Li and
heavy-element production in our universe.

17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
2
The categories of this paper are: math
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
5
The categories of this paper are: gr-qc