Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Varying Light Curve and Timings of the Ultra-short Period Contact
  Binary KIC 9532219   KIC 9532219 is a W UMa-type eclipsing binary with an orbital period of
0.1981549 d that is below the short-period limit ($\sim$0.22 d) of the period
distribution for contact binaries. The {\it Kepler} light curve of the system
exhibits striking light changes in both eclipse depths and light maxima.
Applying third-body and spot effects, the light-curve synthesis indicates that
the eclipsing pair is currently in a marginal contact stage with a mass ratio
of $q$=1.20, an orbital inclination of $i$=66.0 deg, a temperature difference
of $\Delta$ ($T_{1}$--$T_{2}$)=172 K, and a third light of $l_3$=75.9 \%. To
understand the light variations with time, we divided up the light curve into
312 segments and separately analyzed them. The results reveal that variation of
eclipse depth is primarily caused by changing amounts of contamination due to
the nearby star KIC9532228 between the {\it Kepler} Quarters and that the
variable O'Connell effect originates from the starspot activity on the less
massive primary component. Based on our light-curve timings, a period study of
KIC 9532219 indicates that the orbital period has varied as a combination of a
downward parabola and a light-travel-time (LTT) effect due to a third body,
with a period of 1196 d and a minimum mass of 0.0892 $M_\odot$ in an eccentric
orbit of 0.150. The parabolic variation could be a small part of a second LTT
orbit due to a fourth component in a wider orbit, instead of either mass
transfer or angular momentum loss.

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The categories of this paper are: math-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: solv-int
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The categories of this paper are: cs
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The categories of this paper are: cmp-lg
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The categories of this paper are: physics
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The categories of this paper are: q-bio
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The categories of this paper are: hep-th
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The categories of this paper are: supr-con
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The categories of this paper are: acc-phys
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The categories of this paper are: eess
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The categories of this paper are: stat
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The categories of this paper are: q-fin
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The categories of this paper are: adap-org
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-th