J/ApJ/707/1707 Ks-band light curve of CoRoT-1b (Rogers+, 2009)
Ks-band detection of thermal emission and color constraints to CoRoT-1b: a
low-albedo planet with inefficient atmospheric energy redistribution and a
temperature inversion.
Rogers J.C., Apai D., Lopez-Morales M., Sing D.K., Burrows A.
<Astrophys. J., 707, 1707-1716 (2009)>
=2009ApJ...707.1707R 2009ApJ...707.1707R
ADC_Keywords: Photometry, infrared ; Planets ; Stars, double and multiple
Keywords: binaries: eclipsing - planetary systems -
stars: individual (CoRoT-1) - techniques: photometric
Abstract:
We report the detection in Ks-band of the secondary eclipse of the hot
Jupiter CoRoT-1b from time series photometry with the ARC 3.5m
telescope at Apache Point Observatory. The eclipse shows a depth of
0.336±0.042% and is centered at phase 0.5022+0.0023-0.0027,
consistent with a zero eccentricity orbit
(e*cosω=0.0035+0.0036-0.0042). We perform the first optical
to near-infrared multi-band photometric analysis of an exoplanet's
atmosphere and constrain the reflected and thermal emissions by
combining our result with the recent 0.6, 0.71, and 2.09um secondary
eclipse detections by Snellen et al. (2009Natur.459..543S 2009Natur.459..543S), Gillon et
al. (2009, J/A+A/506/359), and Alonso et al. (2009A&A...501L..23A 2009A&A...501L..23A).
Comparing the multi-wavelength detections to state-of-the-art
radiative-convective chemical-equilibrium atmosphere models, we find
the near-infrared fluxes difficult to reproduce. The closest
blackbody-based and physical models provide the following atmosphere
parameters: a temperature T=2460+80-160K; a very low Bond albedo
AB=0.000+0.081-0.000; and an energy redistribution parameter
Pn=0.1, indicating a small but nonzero amount of heat transfer from
the day to nightside. The best physical model suggests a thermal
inversion layer with an extra optical absorber of opacity
κe=0.05cm2/g, placed near the 0.1 bar atmospheric pressure
level. This inversion layer is located 10 times deeper in the
atmosphere than the absorbers used in models to fit mid-infrared
Spitzer detections of other irradiated hot Jupiters.
Description:
We observed two secondary eclipse events of CoRoT-1b on the nights of
2009 January 9 and 15, UT, using the Near-Infrared Camera &
Fabry-Perot Spectrometer (NICFPS) on the ARC 3.5m telescope at Apache
Point Observatory in New Mexico.
Objects:
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RA (2000) DE Designation(s)
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06 48 19.2 -03 06 08 CoRoT-1b = CoRoT-Exo-1b
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 46 757 *Final light curve, calculated by averaging the
point-by-point average of the results from
analyses A and B.
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Notes on table2.dat: The first approach (analysis A) analyzed the combined
dither positions as a single data set. Several stars, including the target,
were isolated enough in the frames to be analyzed by standard aperture
photometry. The second analysis approach (analysis B), analogous to that of
Sing & Lopez-Morales (2009A&A...493L..31S 2009A&A...493L..31S), began with the separation of the
two dither position sets into different light curves, and implemented the
SysRem algorithm (Tamuz et al. 2005MNRAS.356.1466T 2005MNRAS.356.1466T) for de-correlation.
See Figure 2.
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See also:
J/A+A/506/359 : FORS2 and HAWKI photometry of CoRoT-1 (Gillon+, 2009)
J/A+A/482/L17 : CoRoT space mission. I. (Barge+, 2008)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date
15- 24 F10.8 --- Phase Orbital phase
26- 35 F10.8 --- OFlux Observed differential flux in Ks-band
37- 46 F10.8 --- e_OFlux Error in OFlux
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 06-Jan-2012