Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Astrometric orbits of SB9 stars   Hipparcos Intermediate Astrometric Data (IAD) have been used to derive
astrometric orbital elements for spectroscopic binaries from the newly released
Ninth Catalogue of Spectroscopic Binary Orbits (SB9). Among the 1374 binaries
from SB9 which have an HIP entry, 282 have detectable orbital astrometric
motion (at the 5% significance level). Among those, only 70 have astrometric
orbital elements that are reliably determined (according to specific
statistical tests discussed in the paper), and for the first time for 20
systems, representing a 10% increase relative to the 235 DMSA/O systems already
present in the Hipparcos Double and Multiple Systems Annex.
  The detection of the astrometric orbital motion when the Hipparcos IAD are
supplemented by the spectroscopic orbital elements is close to 100% for
binaries with only one visible component, provided that the period is in the 50
- 1000 d range and the parallax is larger than 5 mas. This result is an
interesting testbed to guide the choice of algorithms and statistical tests to
be used in the search for astrometric binaries during the forthcoming ESA Gaia
mission.
  Finally, orbital inclinations provided by the present analysis have been used
to derive several astrophysical quantities. For instance, 29 among the 70
systems with reliable astrometric orbital elements involve main sequence stars
for which the companion mass could be derived. Some interesting conclusions may
be drawn from this new set of stellar masses, like the enigmatic nature of the
companion to the Hyades F dwarf HIP 20935. This system has a mass ratio of 0.98
but the companion remains elusive.

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The categories of this paper are: eess
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The categories of this paper are: econ
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The categories of this paper are: quant-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: cs
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The categories of this paper are: gr-qc
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The categories of this paper are: solv-int
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-th
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The categories of this paper are: q-bio
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The categories of this paper are: ao-sci
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The categories of this paper are: hep-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
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The categories of this paper are: hep-ex
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The categories of this paper are: mtrl-th