Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Limits on the 2.2 microns contrast ratio of the close orbiting planet HD
  189733b   We obtained 238 spectra of the close orbiting extrasolar giant planet HD
189733b with resolution R ~ 15,000 during one night of observations with the
near infrared spectrograph, NIRSPEC, at the Keck II Telescope. We have searched
for planetary absorption signatures in the 2.0 - 2.4 micron region where H_2O
and CO are expected to be the dominant atmospheric opacities. We employ a phase
dependent orbital model and tomographic techniques to search for the planetary
absorption signatures in the combined stellar and planetary spectra. Because
potential absorption signatures are hidden in the noise of each single
exposure, we use a model list of lines to apply a spectral deconvolution. The
resulting mean profile possesses a S/N ratio that is 20 times greater than that
found in individual lines. Our spectral timeseries thus yields spectral
signatures with a mean S/N = 2720. We are unable to detect a planetary
signature at a contrast ratio of log_10(F_p/F_*) = -3.40, with 63.8 per cent
confidence. Our findings are not consistent with model predictions which
nevertheless give a good fit to mid-infrared observations of HD 189733. The
1-sigma result is a factor of 1.7 times less than the predicted 2.185 micron
planet/star flux ratio of log_10(F_p/F_*) ~ -3.16.

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The categories of this paper are: econ
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The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: chao-dyn
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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: hep-th
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The categories of this paper are: comp-gas
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The categories of this paper are: eess
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The categories of this paper are: nlin
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The categories of this paper are: physics
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The categories of this paper are: nucl-ex
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The categories of this paper are: solv-int
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The categories of this paper are: plasm-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: mtrl-th