Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 51 Pegasi - a planet-bearing Maunder minimum candidate   We observed 51 Peg, the first detected planet-bearing star, in a 55 ks
XMM-Newton pointing and in 5 ks pointings each with Chandra HRC-I and ACIS-S.
The star has a very low count rate in the XMM observation, but is clearly
visible in the Chandra images due to the detectors' different sensitivity at
low X-ray energies. This allows a temperature estimate for 51 Peg's corona of
T<1MK; the detected ACIS-S photons can be plausibly explained by emission lines
of a very cool plasma near 200eV. The constantly low X-ray surface flux and the
flat-activity profile seen in optical CaII data suggest that 51 Peg is a
Maunder minimum star; an activity enhancement due to a Hot Jupiter, as proposed
by recent studies, seems to be absent. The star's X-ray fluxes in different
instruments are consistent with the exception of the HRC Imager, which might
have a larger effective area below 200eV than given in the calibration.

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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
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The categories of this paper are: eess
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The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
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The categories of this paper are: nlin