Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Know The Star, Know the Planet. IV. A Stellar Companion to the Host star
  of the Eccentric Exoplanet HD 8673b   HD 8673 hosts a massive exoplanet in a highly eccentric orbit (e=0.723).
Based on two epochs of speckle interferometry a previous publication identified
a candidate stellar companion. We observed HD 8673 multiple times with the 10 m
Keck II telescope, the 5 m Hale telescope, the 3.63 m AEOS telescope and the
1.5m Palomar telescope in a variety of filters with the aim of confirming and
characterizing the stellar companion. We did not detect the candidate
companion, which we now conclude was a false detection, but we did detect a
fainter companion. We collected astrometry and photometry of the companion on
six epochs in a variety of filters. The measured differential photometry
enabled us to determine that the companion is an early M dwarf with a mass
estimate of 0.33-0.45 M?. The companion has a projected separation of 10 AU,
which is one of the smallest projected separations of an exoplanet host binary
system. Based on the limited astrometry collected, we are able to constrain the
orbit of the stellar companion to a semi-major axis of 35{60 AU, an
eccentricity ? 0.5 and an inclination of 75{85?. The stellar companion has
likely strongly in uenced the orbit of the exoplanet and quite possibly
explains its high eccentricity.

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The categories of this paper are: alg-geom
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
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The categories of this paper are: gr-qc
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The categories of this paper are: q-alg
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The categories of this paper are: math-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: funct-an
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The categories of this paper are: eess
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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: plasm-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas