J/A+A/625/A80 WASP-121b secondary eclipse in 2MASS K band (Kovacs+, 2019)
Secondary eclipse of the hot Jupiter WASP-121b at 2 micron.
Kovacs G., Kovacs T.
<Astron. Astrophys. 625, A80 (2019)>
=2019A&A...625A..80K 2019A&A...625A..80K (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry, infrared
Keywords: planets and satellites: atmospheres - methods: data analysis
Abstract:
Ground-based observations of the secondary eclipse in the 2MASS K band
are presented for the hot Jupiter WASP-121b. These are the first
occultation observations of an extrasolar planet that were carried out
with an instrument attached to a 1m class telescope (the SMARTS 1.3m).
We find a highly significant eclipse depth of (0.228±0.023)%.
Together with other planet atmosphere measurements, including the
Hubble Space Telescope near-infrared emission spectrum, current data
support more involved atmosphere models with species producing
emission and absorption features, rather than simple smooth blackbody
emission. Analysis of the time difference between the primary and
secondary eclipses and the durations of these events yields an
eccentricity of e=0.0207±0.0153, which is consistent with the
earlier estimates of low or zero eccentricity, but with a smaller
error. Comparing the observed occultation depth in the K band with the
one derived under the assumption of zero Bond albedo and full heat
redistribution, we find that WASP-121b has a deeper observed
occultation depth than predicted. Together with the sample of 31
systems with K-band occultation data, this observation lends further
support to the idea of inefficient heat transport between the day and
night sides for most of the hot Jupiters.
Description:
Three nights of observation are included, with target and comparison
star fluxes and positions. These data are supplemented by the
detrended target fluxes and weights as used in the paper.
Objects:
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RA (2000) DE Designation(s)
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07 10 24.06 -39 05 50.6 WASP-121 = TYC 7630-352-1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
wasp-121.dat 146 585 The photometric data file
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See also:
J/A+A/623/A57 : WASP-121b Swift UVOT near-UV transit observations (Salz+, 2019)
Byte-by-byte Description of file: wasp-121.dat
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Bytes Format Units Label Explanations
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3 I1 --- NI Night sequence number
5- 6 I2 --- Ndith Dither number
9- 21 F13.5 --- BJD Barycentric Julian Date
25- 32 F8.4 pix Xpos1 X pixel coordinate of the comparison star
35- 42 F8.4 pix Ypos1 Y pixel coordinate of the comparison star
46- 53 F8.2 --- Flux1 Net flux of the comparison star (in ADU unit) (1)
56- 62 F7.5 --- e_Flux1 Relative error of the flux
65- 72 F8.4 pix Xpos2 X pixel coordinate of the target
75- 82 F8.4 pix Ypos2 Y pixel coordinate of the target
86- 93 F8.2 --- Flux2 Net flux of the target (in ADU unit) (1)
96-102 F7.5 --- e_Flux2 Relative error of the flux
104-113 F10.7 --- Phase Orbital phase (2)
116-124 F9.7 --- DFlux ?=9.999999 Detrended relative flux of the
target (3)
127-135 F9.7 --- Trap ?=9.999999 Best trapezoidal fit to DFLUX (4)
139-146 F8.6 --- W ?=9.999999 DFLUX weights (5)
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Note (1): Fluxes are corrected for background.
Fluxes are assumed to be Poissonian, i.e., RE=1/Flux0.5.
Note (2): PHASE is calculated from Porb=1.2749255 d,
Tocc=2457764.65485, yielding zero phase at the occultation center.
Note (3): Detrended flux DFlux is normalized to unity in the out-of-eclipse
part.
Invalid items, due to data clipping (see paper), are flagged by 9.999999.
Note (4): The ingress/egress times for TRAP are fixed as given by the transit.
Invalid items, due to data clipping (see paper), are flagged by 9.999999.
Note (5): The sum of the weights is equal to the number of detrended data
points.
Invalid items, due to data clipping (see paper), are flagged by 9.999999.
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Acknowledgements:
Geza Kovacs, kovageza(at)gmail.com
(End) Patricia Vannier [CDS] 26-Apr-2019