Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Eclipsing binaries in the open cluster NGC 2243 - II. Absolute
  properties of NV CMa   We present echelle spectroscopic data for five eclipsing binary stars and two
giant stars in the field of the open cluster NGC 2243. The average cluster
velocity is determined to be +60.4 +- 0.6 km/s. Four of the eclipsing binaries
are very likely members of the cluster based on their observed radial
velocities. The absolute parameters of cluster member NV CMa are determined by
analysing photometric and radial velocity data. We obtain 1.089+-0.010 Msun and
1.221+-0.031 Rsun for the primary, and 1.069+-0.010 Msun and 178+-0.037 Rsun
for the secondary. Both components of the binary are located on the Main
Sequence, about 1 mag. below the turn-off point on the cluster color-magnitude
diagram. Using model age-luminosity and age-radius relations we obtain
4.35+-0.25 Gyr for the age of NV CMa. The derived age is, however, very
sensitive to the adopted metallicity of the cluster. We demonstrate that a
meaningful determination of the ages of objects like NV CMa based on
evolutionary models is possible only if their metallicity is know with a
relative accuracy of a few percent. The distance moduli calculated for the
components of NV CMa agree closely with each other, and imply an apparent
distance modulus of the cluster of (m-M)_V=13.25+-0.08.

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The categories of this paper are: stat
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The categories of this paper are: cond-mat
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The categories of this paper are: q-fin
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The categories of this paper are: ao-sci
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The categories of this paper are: solv-int
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The categories of this paper are: nlin
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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: math-ph
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: physics
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The categories of this paper are: nucl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: gr-qc