Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Very Low-Mass Stellar and Substellar Companions to Solar-like Stars From
  MARVELS VI: A Giant Planet and a Brown Dwarf Candidate in a Close Binary
  System HD 87646   We report the detections of a giant planet (MARVELS-7b) and a brown dwarf
candidate (MARVELS-7c) around the primary star in the close binary system, HD
87646. It is the first close binary system with more than one substellar
circum-primary companion discovered to the best of our knowledge. The detection
of this giant planet was accomplished using the first multi-object Doppler
instrument (KeckET) at the Sloan Digital Sky Survey (SDSS) telescope.
Subsequent radial velocity observations using ET at Kitt Peak National
Observatory, HRS at HET, the "Classic" spectrograph at the Automatic
Spectroscopic Telescope at Fairborn Observatory, and MARVELS from SDSS-III
confirmed this giant planet discovery and revealed the existence of a
long-period brown dwarf in this binary. HD 87646 is a close binary with a
separation of $\sim22$ AU between the two stars, estimated using the Hipparcos
catalogue and our newly acquired AO image from PALAO on the 200-inch Hale
Telescope at Palomar. The primary star in the binary, HD 87646A, has Teff =
5770$\pm$80K, log(g)=4.1$\pm$0.1 and [Fe/H] = $-0.17\pm0.08$. The derived
minimum masses of the two substellar companions of HD 87646A are
12.4$\pm$0.7M$_{\rm Jup}$ and 57.0$\pm3.7$M$_{\rm Jup}$. The periods are
13.481$\pm$0.001 days and 674$\pm$4 days and the measured eccentricities are
0.05$\pm$0.02 and 0.50$\pm$0.02 respectively. Our dynamical simulations show
the system is stable if the binary orbit has a large semi-major axis and a low
eccentricity, which can be verified with future astrometry observations.

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The categories of this paper are: econ
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The categories of this paper are: hep-lat
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The categories of this paper are: math
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The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: nucl-ex
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The categories of this paper are: cs
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The categories of this paper are: q-alg
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The categories of this paper are: mtrl-th
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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: nlin
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The categories of this paper are: quant-ph