Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Detection of the Molecular Zeeman Effect in Circular Polarization on
  Cool Active Stars   We report on the first ever detection of circular polarization in molecular
lines forming in magnetic regions on the surfaces of active stars. The new
observations were obtained with the high-resolution spectropolarimeter ESPaDOnS
recently installed at the Canada-France-Hawaii Telescope. In July 2005 we
carried out a survey of 17 G-K-M stars including active main-sequence dwarfs
and RS CVn-type giants and subgiants. All stars were found to possess surface
magnetic fields producing average atomic Stokes V signals of 0.05% to 0.5%.
Three stars clearly showed circular polarization in molecular lines of 0.5% to
1%. The molecular Stokes V signal is reminiscent of that observed in sunspots.

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The categories of this paper are: bayes-an
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The categories of this paper are: acc-phys
3
The categories of this paper are: physics
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The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: atom-ph
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The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-bio
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The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: stat
17
The categories of this paper are: q-fin