Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Possible chromospheric activity cycles in II Peg, UX Ari and V711 Tau   We study the Mount Wilson indices we obtained indirectly from IUE high and
low resolution spectra of the RS CVn-type systems II Peg (K2IV), UX Ari
(K0IV+G5V) and V711 Tau (K1IV+G5V), extensively observed by IUE from 1978 to
1996. We analyze the activity signatures, which correspond to the primary star,
with the Lomb-Scargle periodogram. From the analysis of V711 Tau data, we found
a possible chromospheric cycle with a period of 18 years and a shorter near
3-year cycle, which could be associated to a chromospheric flip-flop cycle. The
data of II Peg also suggest a chromospheric cycle of near 21 years and a
flip-flop cycle of 9 years approximately. Finally, we obtained a possible
chromospheric cycle of near 6 years for UX Ari.

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The categories of this paper are: supr-con
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The categories of this paper are: acc-phys
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The categories of this paper are: cmp-lg
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The categories of this paper are: math
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: plasm-ph
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The categories of this paper are: physics
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The categories of this paper are: econ
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The categories of this paper are: ao-sci
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-th
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The categories of this paper are: stat
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The categories of this paper are: q-bio
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The categories of this paper are: quant-ph