Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Rotational modulation and single g-mode pulsation in the B9pSi star
  HD174356?   Chemically peculiar (CP) stars of the upper main sequence are characterised
by specific anomalies in the photospheric abundances of some chemical elements.
The group of CP2 stars, which encompasses classical Ap and Bp stars, exhibits
strictly periodic light, spectral, and spectropolarimetric variations that can
be adequately explained by the model of a rigidly rotating star with persistent
surface structures and a stable global magnetic field. Using observations from
the Kepler K2 mission, we find that the B9pSi star HD 174356 displays a light
curve both variable in amplitude and shape, which is not expected in a CP2
star. Employing archival and new photometric and spectroscopic observations, we
carry out a detailed abundance analysis of HD 174356 and discuss its
photometric and astrophysical properties in detail. We employ phenomenological
modeling to decompose the light curve and the observed radial velocity
variability. Our abundance analysis confirms that HD 174356 is a silicon-type
CP2 star. No magnetic field stronger than 110G was found. The star's light
curve can be interpreted as the sum of two independent strictly periodic
signals with P1 = 4.04355(5)d and P2 = 2.11169(3)d. The periods have remained
stable over 17 years of observations. In all spectra, HD 174356 appears to be
single-lined. From the simulation of the variability characteristics and
investigation of stars in the close angular vicinity, we put forth the
hypothesis that the peculiar light variability of HD 174356 arises in a single
star and is caused by rotational modulation due to surface abundance patches
(P1) and g mode pulsation (P2).

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The categories of this paper are: math
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
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The categories of this paper are: chao-dyn
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
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The categories of this paper are: hep-ex
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The categories of this paper are: nlin
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol