Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the competing effect of wind braking and interior coupling in the
  rotational evolution of solar-like stars   Solar-like stars (M < 1.3 Msun) lose angular momentum through their
magnetized winds. The resulting evolution of the surface rotation period, which
can be directly measured photometrically, has the potential to provide an
accurate indicator of stellar age, and is constrained by observations of
rotation periods of coeval stars, such as members of Galactic open clusters. A
prominent observational feature of the mass-rotation period diagrams of open
clusters is a sequence of relatively slower rotators. The formation and
persistence of this slow rotators sequence across several billion years imply
an approximately coherent spin-down of the stars that belong to it. In
particular, the sequence is observed to evolve coherently towards longer
periods in progressively older clusters. Recent observations of the 700-Myr old
Praesepe and the 1-Gyr old NGC 6811 clusters, however, seem to contradict this
general pattern. While the 1 Msun stars on the slow rotators sequence of the
older NGC 6811 have longer periods than their counterparts in the younger
Praesepe, as expected, the two sequences essentially merge at lower masses (<
0.8 Msun). In other words, low-mass stars seem to have not been spinning down
at all in the intervening 300 Myr. Here we show that this behavior is a
manifestation of the variable rotational coupling in solar-like stars. The
resurfacing of angular momentum from the interior can temporarily compensate
for the loss due to wind braking at the surface. The internal redistribution of
angular momentum has a steep mass dependence; as a result, the re-coupling
occurs at different ages for stars of different masses. Our model explains the
stalled surface spin-down of low-mass stars between Praesepe and NGC 6811, and
predicts that the same behavior should be observable at other ages in other
mass ranges.

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The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
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The categories of this paper are: solv-int
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The categories of this paper are: atom-ph
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The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex