Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Formation, tidal evolution and habitability of the Kepler-186 system   The Kepler-186 system consists of five planets orbiting an early-M dwarf. The
planets have physical radii of 1.0-1.50 R$_\oplus$ and orbital periods of 4 to
130 days. The $1.1~$R$_\oplus$ Kepler-186f with a period of 130 days is of
particular interest. Its insolation of roughly $0.32~S_\odot$places it within
the liquid water habitable zone. We present a multi-faceted study of the
Kepler-186 system. First, we show that the distribution of planet masses can be
roughly reproduced if the planets accreted from a high-surface density disk
presumably sculpted by an earlier phase of migration. However, our simulations
predict the existence of 1-2 undetected planets between planets e and f. Next,
we present a dynamical analysis of the system including the effect of tides.
The timescale for tidal evolution is short enough that the four inner planets
must have small obliquities and near-synchronous rotation rates. Tidal
evolution of Kepler-186f is slow enough that its current spin state depends on
a combination of its dissipation rate and the stellar age. Finally, we study
the habitability of Kepler-186f with a 1-D climate model. The planet's surface
temperature can be raised above 273 K with 0.5-5 bars of CO$_2$, depending on
the amount of N$_2$ present. Kepler-186f represents a case study of an
Earth-sized planet in the cooler regions of the habitable zone of a cool star.

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The categories of this paper are: ao-sci
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The categories of this paper are: bayes-an
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The categories of this paper are: atom-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: adap-org
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th
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The categories of this paper are: plasm-ph
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The categories of this paper are: eess
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The categories of this paper are: dg-ga
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The categories of this paper are: math
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The categories of this paper are: supr-con
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The categories of this paper are: physics
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The categories of this paper are: hep-th
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The categories of this paper are: hep-lat