Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Using planetary transits to estimate magnetic cycles lengths in Kepler
  stars   Observations of various solar-type stars along decades revealed that they can
have magnetic cycles, just like our Sun. An investigation of the relation
between their cycle length and rotation period can shed light on the dynamo
mechanisms operating in these stars. Previous works on this relation suggested
that the stars could be separated into active and inactive branches, with the
Sun falling between them. In this work, we determined short magnetic activity
cycles for 6 active solar-type stars observed by the Kepler telescope. The
method adopted here estimates the activity from the excess in the residuals of
the transitlight curves. This excess is obtained by subtracting a spotless
model transit from the light curve, and then integrating over all the residuals
during the transit. The presence of long term periodicity is estimated from the
analysis of a Lomb-Scargle periodogram of the complete time series. Finally, we
investigate the rotation-cycle period relation for the stars analysed here and
find that some active stars do not follow the behaviour proposed earlier,
falling in the inactive branch. In addition, we also notice a considerable
spread from other stars in the literature in the active/inactive branches.

14
The categories of this paper are: math-ph
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con