Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A binary engine fuelling HD87643' s complex circumstellar environment,
  using AMBER/VLTI   Context. The star HD 87643, exhibiting the "B[e] phenomenon", has one of the
most extreme infrared excesses for this object class. It harbours a large
amount of both hot and cold dust, and is surrounded by an extended reflection
nebula. Aims. One of our major goals was to investigate the presence of a
companion in HD87643. In addition, the presence of close dusty material was
tested through a combination of multi-wavelength high spatial 5Aresolution
observations. Methods. We observed HD 87643 with high spatial resolution
techniques, using the near-IR AMBER/VLTI interferometer with baselines ranging
from 60 m to 130 m and the mid-IR MIDI/VLTI interferometer with baselines
ranging from 25 m to 65 m. These observations are complemented by NACO/VLT
adaptive-optics-corrected images in the K and L-bands, ESO-2.2m optical
Wide-Field Imager large-scale images in the B, V and R-bands, Results. We
report the direct detection of a companion to HD 87643 by means of image
synthesis using the AMBER/VLTI instrument. The presence of the companion is
confirmed by the MIDI and NACO data, although with a lower confidence. The
companion is separated by ~ 34 mas with a roughly north-south orientation. The
period must be large (several tens of years) and hence the orbital parameters
are not determined yet. Binarity with high eccentricity might be the key to
interpreting the extreme characteristics of this system, namely a dusty
circumstellar envelope around the primary, a compact dust nebulosity around the
binary system and a complex extended nebula witnessing past violent ejections.

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The categories of this paper are: hep-th
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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: physics
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The categories of this paper are: comp-gas
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The categories of this paper are: atom-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: dg-ga
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The categories of this paper are: nlin
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom
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The categories of this paper are: math-ph
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The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: math
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The categories of this paper are: nucl-th