Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Evolving Radio Photospheres of Long-Period Variable Stars   Observations with the Karl G. Jansky Very Large Array at 46 GHz (7 mm) have
been used to measure the size and shape of the radio photospheres of four
long-period variable stars: R Leonis (R Leo), IRC+10216 (CW Leo), chi Cygni
(chi Cyg), and W Hydrae (W Hya). The shapes of the stars range from nearly
round to ellipticities of ~0.15. Comparisons with observations taken several
years earlier show that the photospheric parameters (mean diameter, shape,
and/or flux density) of each of the stars have changed over time. Evidence for
brightness asymmetries and non-uniformities across the radio surfaces are also
seen in the visibility domain and in images obtained using a sparse modeling
image reconstruction technique. These trends may be explained as manifestations
of large-scale irregular convective flows on the stellar surface, although
effects from non-radial pulsations cannot be excluded. Our data also allow a
new evaluation of the proper motion of IRC+10216. Our measurement is in
agreement with previous values obtained from radio wavelength measurements, and
we find no evidence of statistically significant astrometric perturbations from
a binary companion.

21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
16
The categories of this paper are: stat
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph