J/ApJ/788/92 The hot Jupiter Kepler-13Ab planet's occultation (Shporer+, 2014)
Atmospheric characterization of the hot Jupiter Kepler-13Ab.
Shporer A., O'Rourke J.G., Knutson H.A., Szabo G.M., Zhao M., Burrows A.,
Fortney J., Agol E., Cowan N.B., Desert J.-M., Howard A.W., Isaacson H.,
Lewis N.K., Showman A.P., Todorov K.O.
<Astrophys. J., 788, 92 (2014)>
=2014ApJ...788...92S 2014ApJ...788...92S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Planets ; Photometry, infrared ;
Spectroscopy
Keywords: planetary systems - stars: early-type -
stars: individual: Kepler-13, BD+46 2629 - techniques: photometric -
techniques: spectroscopic
Abstract:
Kepler-13Ab (= KOI-13.01) is a unique transiting hot Jupiter. It is
one of very few known short-period planets orbiting a hot A-type star,
making it one of the hottest planets currently known. The availability
of Kepler data allows us to measure the planet's occultation
(secondary eclipse) and phase curve in the optical, which we combine
with occultations observed by warm Spitzer at 4.5 µm and 3.6 µm
and a ground-based occultation observation in the Ks band (2.1 µm).
We derive a day-side hemisphere temperature of 2750±160 K as the
effective temperature of a black body showing the same occultation
depths. Comparing the occultation depths with one-dimensional
planetary atmosphere models suggests the presence of an atmospheric
temperature inversion. Our analysis shows evidence for a relatively
high geometric albedo, Ag=0.33-0.06+0.04. While measured with a
simplistic method, a high Ag is supported also by the fact that the
one-dimensional atmosphere models underestimate the occultation depth
in the optical. We use stellar spectra to determine the dilution, in
the four wide bands where occultation was measured, due to the visual
stellar binary companion 1.15"±0.05" away. The revised stellar
parameters measured using these spectra are combined with other
measurements, leading to revised planetary mass and radius estimates
of Mp=4.94-8.09 MJ and Rp=1.406±0.038 RJ. Finally, we
measure a Kepler midoccultation time that is 34.0±6.9 s earlier than
expected based on the midtransit time and the delay due to
light-travel time and discuss possible scenarios.
Description:
Here we carry out an atmospheric characterization of Kepler-13Ab by
measuring its occultation in four different wavelength bands, from the
infrared (IR; Spitzer/Infrared array camera (IRAC) 4.5 um and
3.6 um), through the near-IR (NIR; Ks band), to the optical
(Kepler). We also analyze the Kepler phase curve and obtain
Keck/high-resolution echelle spectrometer (HIRES) spectra that result
in revised parameters for the objects in the system.
Objects:
-------------------------------------------------------
RA (ICRS) DE Designation(s)
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19 07 53.15 +46 52 05.9 Kepler-13Ab = KOI-13.01
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 62 3700 Spitzer 4.5 micron light curve
table2.dat 62 11084 Spitzer 3.6 micron light curve
table3.dat 38 1101 WIRC Ks light curve
table8.dat 36 49019 Kepler-13A/Kepler-13B Flux Ratio
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See also:
II/295 : Spitzer IRAC survey of the galactic center (Ramirez+, 2008)
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/A+A/508/1509 : Sky maps for hot Jupiters (Heller+, 2009)
J/A+A/544/L12 : Velocitometry transit of KOI-13 (Santerne+, 2012)
J/AJ/143/39 : Analysis of hot Jupiters in Kepler Q2 (Coughlin+, 2012)
Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 15 F15.7 d Time Barycentric Julian date of mid-exposure
17- 25 F9.5 pix Xpix X pixel coordinate
27- 35 F9.5 pix Ypix Y pixel coordinate
37- 44 F8.6 --- RFlux Raw relative flux (1)
46- 53 F8.6 --- e_RFlux Error in RFlux
55- 62 F8.6 --- DFlux Detrended relative flux (2)
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Note (1): Without correcting for the intra-pixel sensitivity variations.
Note (2): After removing all variabilities except the occultation.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d Time Barycentric Julian date of mid-exposure
16- 22 F7.5 --- RFlux Raw relative flux (1)
24- 30 F7.5 --- e_RFlux Error in RFlux
32- 38 F7.5 --- DFlux Detrended relative flux (2)
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Note (1): Without correcting for the long term trend.
Note (2): After removing the long term temporal trend.
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 0.1nm Wave Wavelength; Angstroms
11- 18 F8.6 --- FRatio Flux ratio
20- 27 F8.6 --- E_FRatio The 1σ upper boundary on FRatio
29- 36 F8.6 --- e_FRatio The 1σ lower boundary on FRatio
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 10-Jul-2017