Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Size and Shape Constraints of (486958) Arrokoth from Stellar
  Occultations   We present the results from four stellar occultations by (486958) Arrokoth,
the flyby target of the New Horizons extended mission. Three of the four
efforts led to positive detections of the body, and all constrained the
presence of rings and other debris, finding none. Twenty-five mobile stations
were deployed for 2017 June 3 and augmented by fixed telescopes. There were no
positive detections from this effort. The event on 2017 July 10 was observed by
SOFIA with one very short chord. Twenty-four deployed stations on 2017 July 17
resulted in five chords that clearly showed a complicated shape consistent with
a contact binary with rough dimensions of 20 by 30 km for the overall outline.
A visible albedo of 10% was derived from these data. Twenty-two systems were
deployed for the fourth event on 2018 Aug 4 and resulted in two chords. The
combination of the occultation data and the flyby results provides a
significant refinement of the rotation period, now estimated to be 15.9380
$\pm$ 0.0005 hours. The occultation data also provided high-precision
astrometric constraints on the position of the object that were crucial for
supporting the navigation for the New Horizons flyby. This work demonstrates an
effective method for obtaining detailed size and shape information and probing
for rings and dust on distant Kuiper Belt objects as well as being an important
source of positional data that can aid in spacecraft navigation that is
particularly useful for small and distant bodies.

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The categories of this paper are: funct-an
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The categories of this paper are: adap-org
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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: chem-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: stat
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The categories of this paper are: cs
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The categories of this paper are: hep-ex
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The categories of this paper are: cond-mat
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The categories of this paper are: nlin
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-th
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The categories of this paper are: mtrl-th