Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dusty shells surrounding the carbon variables S Scuti and RT Capricorni   For the Mass-loss of Evolved StarS (MESS) programme, the unprecedented
spatial resolution of the PACS photometer on board the Herschel space
observatory was employed to map the dusty environments of asymptotic giant
branch (AGB) and red supergiant (RSG) stars. Among the morphologically
heterogeneous sample, a small fraction of targets is enclosed by spherically
symmetric detached envelopes. Based on observations in the 70 {\mu}m and 160
{\mu}m wavelength bands, we investigated the surroundings of the two carbon
semiregular variables S Sct and RT Cap, which both show evidence for a history
of highly variable mass-loss. S Sct exhibits a bright, spherically symmetric
detached shell, 138" in diameter and co-spatial with an already known CO
structure. Moreover, weak emission is detected at the outskirts, where the
morphology seems indicative of a mild shaping by interaction of the wind with
the interstellar medium, which is also supported by the stellar space motion.
Two shells are found around RT Cap that were not known so far in either dust
emission or from molecular line observations. The inner shell with a diameter
of 188" shows an almost immaculate spherical symmetry, while the outer ~5'
structure is more irregularly shaped. MoD, a modification of the DUSTY
radiative transfer code, was used to model the detached shells. Dust
temperatures, shell dust masses, and mass-loss rates are derived for both
targets.

20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph