Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The DEdicated MONitor of EXotransits (DEMONEX): Seven Transits of XO-4b   The DEdicated MONitor of EXotransits (DEMONEX) was a 20 inch robotic and
automated telescope to monitor bright stars hosting transiting exoplanets to
discover new planets and improve constraints on the properties of known
transiting planetary systems. We present results for the misaligned hot Jupiter
XO-4b containing 7 new transits from the DEMONEX telescope, including 3 full
and 4 partial transits. We combine these data with archival light curves and
archival radial velocity measurements to derive the host star mass
$M_{*}=1.293_{-0.029}^{+0.030} M_\odot$ and radius
$R_{*}=1.554_{-0.030}^{+0.042} R_\odot$ as well as the planet mass
$M_{P}=1.615_{-0.099}^{+0.10} M_{\rm J}$ and radius
$R_{P}=1.317_{-0.029}^{+0.040} R_{\rm J}$ and a refined ephemeris of
$P=4.1250687\pm0.0000024$ days and $T_{0}=2454758.18978\pm0.00024 \rm
{BJD_{TDB}}$. We include archival Rossiter-McLaughlin measurements of XO-4 to
infer the stellar spin-planetary orbit alignment $\lambda=-40.0_{-7.5}^{+8.8}$
degrees.
  We test the effects of including various detrend parameters, theoretical and
empirical mass-radius relations, and Rossiter-McLaughlin models. We infer that
detrending against CCD position and time or airmass can improve data quality,
but can have significant effects on the inferred values of many parameters ---
most significantly $R_{P}/R_{*}$ and the observed central transit times
$T_{C}$. In the case of $R_{P}/R_{*}$ we find that the systematic uncertainty
due to detrending can be three times that of the quoted statistical
uncertainties. The choice of mass-radius relation has little effect on our
inferred values of the system parameters. The choice of Rossiter-McLaughlin
models can have significant effects of the inferred values of $v\sin{I_{*}}$
and the stellar spin-planet orbit angle $\lambda$.

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The categories of this paper are: quant-ph
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The categories of this paper are: stat
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The categories of this paper are: nucl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-lat
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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: chao-dyn
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The categories of this paper are: nlin
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The categories of this paper are: plasm-ph
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The categories of this paper are: q-alg
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The categories of this paper are: eess
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The categories of this paper are: cond-mat
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The categories of this paper are: math
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The categories of this paper are: q-fin