Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin-Orbit Alignment of the TrES-4 Transiting Planetary System and
  Possible Additional Radial Velocity Variation   We report new radial velocities of the TrES-4 transiting planetary system,
including observations of a full transit, with the High Dispersion Spectrograph
of the Subaru 8.2m telescope. Modeling of the Rossiter-McLaughlin effect
indicates that TrES-4b has closely aligned orbital and stellar spin axes, with
$\lambda = 6.3^{\circ} \pm 4.7^{\circ}$. The close spin-orbit alignment angle
of TrES-4b seems to argue against a migration history involving planet-planet
scattering or Kozai cycles, although there are two nearby faint stars that
could be binary companion candidates. Comparison of our out-of-transit data
from 4 different runs suggest that the star exhibits radial velocity
variability of $\sim$20 ms^-1 in excess of a single Keplerian orbit. Although
the cause of the excess radial velocity variability is unknown, we discuss
various possibilities including systematic measurement errors, starspots or
other intrinsic motions, and additional companions besides the transiting
planet.

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The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
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The categories of this paper are: q-fin
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The categories of this paper are: eess
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
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The categories of this paper are: funct-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph