Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Brightness of Starlink and OneWeb Satellites During Ingress and
  Egress from Terrestrial Eclipses   A model that combines celestial geometry and atmospheric physics is used to
calculate the dimming of artificial satellites as they enter and exit the
Earth's shadow. Refraction of sunlight by the terrestrial atmosphere can
illuminate a satellite while it is inside the eclipse region determined from
geometry alone. Meanwhile, refraction combines with atmospheric absorption to
dim the satellites for tens of km outside of that region. Spacecraft brightness
is reduced more in blue light than in red because absorption of sunlight is
stronger at shorter wavelengths. Observations from the MMT-9 robotic
observatory are consistent with the model predictions. Tables of satellite
brightness as functions of their location in the eclipse region are provided.

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The categories of this paper are: math
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: dg-ga
3
The categories of this paper are: physics
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The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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The categories of this paper are: eess
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-th