Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multiperiodicity, modulations and flip-flops in variable star light
  curves III. Carrier fit analysis of LQ Hya photometry for 1982-2014   We study LQ Hya photometry for 1982-2014 with the carrier fit (CF) -method
and compare our results to earlier photometric analysis and recent Doppler
imaging maps. We first utilize different types of statistical methods to
estimate various candidates for the carrier period for the CF method. Secondly,
a global fit to the whole data set and local fits to shorter segments are
computed with the period that is found to be the optimal one. The harmonic
least-squares analysis of all the available data reveals a short period close
to 1.6 days as a limiting value for a set of significant frequencies. We
interpret this as the rotation period of the spots near the equatorial region.
In addition, the distribution of the significant periods is found to be
bimodal, hinting of a longer-term modulating period, which we set out to study
with a two-harmonic CF model. Weak modulation signal is, indeed retrieved, with
a period of roughly 6.9 years. The phase dispersion analysis gives a clear
symmetric minimum for coherence times lower than and around 100 days. We
interpret this as the mean rotation period of the spots (1.60514 days), and
this value is chosen to be used as the carrier period for the CF analysis. With
the CF method we seek for any systematic trends in the spot distribution in the
global time frame, and locally look for abrupt phase changes earlier reported
in rapidly rotating objects. During 2005-2008 the global CF reveals a coherent
structure rotating with a period of 1.6037 days, while during most other times
the spot distribution appears rather random in phase. The evolution of the spot
distribution of the object is found to be very chaotic, with no clear signs of
an azimuthal dynamo wave that would persist over longer time scales, although
the short-lived coherent structures observed occasionally do not rotate with
the same speed as the mean spot distribution.

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The categories of this paper are: funct-an
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The categories of this paper are: patt-sol
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The categories of this paper are: cmp-lg
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The categories of this paper are: acc-phys
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: stat
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The categories of this paper are: hep-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-ex
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The categories of this paper are: physics
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The categories of this paper are: eess
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The categories of this paper are: chem-ph