Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unusual Phase Reversal of Superhumps in ER Ursae Majoris   We studied the evolution of superhumps in the peculiar SU UMa-type dwarf
nova, ER UMa. Contrary to the canonical picture of the SU UMa-type superhump
phenomena, the superhumps of ER UMa show an unexpected phase reversal during
the very early stage (~5 d after the superoutburst maximum). We interpret that
a sudden switch to so-called late superhumps occurs during the very early stage
of a superoutburst. What had been believed to be (ordinary) superhumps during
the superoutburst plateau of ER UMa were actually late superhumps. The
implication of this discovery is briefly discussed.

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The categories of this paper are: cond-mat
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The categories of this paper are: supr-con
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The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
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The categories of this paper are: chem-ph
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
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The categories of this paper are: stat
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The categories of this paper are: nlin
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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
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The categories of this paper are: q-bio
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The categories of this paper are: q-fin
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The categories of this paper are: chao-dyn