Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: UBVRI photopolarimetry of the long period eclipsing AM Herculis binary
  V1309   We report simultaneous UBVRI photo-polarimetric observations of the long
period (7.98 h) AM Her binary V1309 Ori. The length and shape of the eclipse
ingress and egress varies from night to night. We suggest this is due to the
variation in the brightness of the accretion stream. By comparing the phases of
circular polarization zero-crossovers with previous observations, we confirm
that V1309 Ori is well synchronized, and find an upper limit of 0.002 percent
for the difference between the spin and orbital periods. We model the
polarimetry data using a model consisting of two cyclotron emission regions at
almost diametrically opposite locations, and centered at colatitude 35 (deg)
and 145 (deg) on the surface of the white dwarf. We also present archive X-ray
observations which show that the negatively polarised accretion region is X-ray
bright.

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The categories of this paper are: atom-ph
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The categories of this paper are: physics
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The categories of this paper are: q-fin
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-th
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The categories of this paper are: math
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-lat
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
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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: gr-qc
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The categories of this paper are: hep-ex