Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Confirmation of an exoplanet using the transit color signature:
  Kepler-418b, a blended giant planet in a multiplanet system   We announce confirmation of Kepler-418b, one of two proposed planets in this
system. This is the first confirmation of an exoplanet based primarily on the
transit color signature technique. We used the Kepler public data archive
combined with multicolor photometry from the Gran Telescopio de Canarias and
radial velocity follow-up using FIES at the Nordic Optical Telescope for
confirmation. We report a confident detection of a transit color signature that
can only be explained by a compact occulting body, entirely ruling out a
contaminating eclipsing binary, a hierarchical triple, or a grazing eclipsing
binary. Those findings are corroborated by our radial velocity measurements,
which put an upper limit of ~1 Mjup on the mass of Kepler-418b. We also report
that the host star is significantly blended, confirming the ~10% light
contamination suspected from the crowding metric in the Kepler light curve
measured by the Kepler team. We report detection of an unresolved light source
that contributes an additional ~40% to the target star, which would not have
been detected without multicolor photometric analysis. The resulting
planet-star radius ratio is 0.110 +/- 0.0025, more than 25% more than the 0.087
measured by Kepler, leading to a radius of 1.20 +/- 0.16 Rjup instead of the
0.94 Rjup measured by the Kepler team. This is the first confirmation of an
exoplanet candidate based primarily on the transit color signature,
demonstrating that this technique is viable from ground for giant planets. It
is particularly useful for planets with long periods such as Kepler-418b, which
tend to have long transit durations. Additionally, multicolor photometric
analysis of transits can reveal unknown stellar neighbors and binary companions
that do not affect the classification of the transiting object but can have a
very significant effect on the perceived planetary radius.

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The categories of this paper are: cs
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The categories of this paper are: funct-an
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The categories of this paper are: acc-phys
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The categories of this paper are: solv-int
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The categories of this paper are: alg-geom
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The categories of this paper are: q-alg
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The categories of this paper are: q-fin
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The categories of this paper are: math
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: econ
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-lat
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The categories of this paper are: hep-ph
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The categories of this paper are: chao-dyn