Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: WIYN Open Cluster Study. XXIV. Stellar Radial-Velocity Measurements in
  NGC 6819   We present the current results from our ongoing radial-velocity survey of the
intermediate-age (2.4 Gyr) open cluster NGC 6819. Using both newly observed and
other available photometry and astrometry we define a primary target sample of
1454 stars that includes main-sequence, subgiant, giant, and blue straggler
stars, spanning a magnitude range of 11<=V<=16.5 and an approximate mass range
of 1.1 to 1.6 Msun. Our sample covers a 23 arcminute (13 pc) square field of
view centered on the cluster. We have measured 6571 radial velocities for an
unbiased sample of 1207 stars in the direction of the open cluster NGC 6819,
with a single-measurement precision of 0.4 km/s for most narrow-lined stars. We
use our radial-velocity data to calculate membership probabilities for stars
with >= 3 measurements, providing the first comprehensive membership study of
the cluster core that includes stars from the giant branch through the upper
main sequence. We identify 480 cluster members. Additionally, we identify
velocity-variable systems, all of which are likely hard binaries that
dynamically power the cluster. Using our single cluster members, we find a
cluster average radial velocity of 2.34 +/- 0.05 km/s . We use our kinematic
cluster members to construct a cleaned color- magnitude diagram from which we
identify rich giant, subgiant, and blue straggler populations and a
well-defined red clump. The cluster displays a morphology near the cluster
turnoff clearly indicative of core convective overshoot. Finally, we discuss a
few stars of note, one of which is a short-period red-clump binary that we
suggest may be the product of a dynamical encounter.

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The categories of this paper are: cs
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The categories of this paper are: mtrl-th
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The categories of this paper are: stat
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The categories of this paper are: quant-ph
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The categories of this paper are: math-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: cond-mat
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The categories of this paper are: nlin
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The categories of this paper are: chao-dyn
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The categories of this paper are: physics
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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-th
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The categories of this paper are: q-bio
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The categories of this paper are: hep-lat