Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Detection of Discrete Cyclotron Emission Features in Phase-Resolved
  Optical Spectroscopy of V1500 Cygni   We have obtained phase-resolved optical spectroscopy of the old nova, and
asynchronous polar V1500 Cyg. These new data reveal discrete cyclotron humps
from two different strength magnetic fields. One region has B = 72 MG, while
the other has B ~ 105 MG. With the detection of these features, we revisit the
optical/near-IR light curves presented in Harrison & Campbell (2016), and find
that the large photometric excesses observed in those data are fully
reconcilable with cyclotron emission. These results, when combined with the
X-ray observations that appeared to have maxima that repeated on the orbital
period, imply that V1500 Cyg has reverted back to a synchronous polar. Using
existing theory, we show that the strong field strengths found here can explain
the rapid spin down time.

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The categories of this paper are: q-fin
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The categories of this paper are: econ
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The categories of this paper are: dg-ga
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The categories of this paper are: alg-geom
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The categories of this paper are: cond-mat
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The categories of this paper are: quant-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: solv-int
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The categories of this paper are: adap-org
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: nlin
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The categories of this paper are: hep-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: math-ph
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The categories of this paper are: q-alg