J/A+A/685/A63 WASP-12b CHEOPS light curves (Akinsanmi+, 2024)
The tidal deformation and atmosphere of WASP-12b from its phase curve.
Akinsanmi B., Barros S.C.C., Lendl M., Carone L., Cubillos P.E.,
Bekkelien A., Fortier A., Floren H.-G., Collier Cameron A., Boue G.,
Bruno G., Demory B.-O., Brandeker A., Sousa S.G., Wilson T.G., Deline A.,
Bonfanti A., Scandariato G., Hooton M.J., Correia A.C.M., Demangeon O.D.S.,
Smith A.M.S., Singh V., Alibert Y., Alonso R., Asquier J., Barczy T.,
Barrado Navascues D., Baumjohann W., Beck M., Beck T., Benz W., Billot N.,
Bonfils X., Borsato L., Broeg Ch., Buder M., Charnoz S., Csizmadia Sz.,
Davies M.B., Deleuil M., Delrez L., Ehrenreich D., Erikson A., Farinato J.,
Fossati L., Fridlund M., Gandolfi D., Gillon M., Guedel M., Guenther M.N.,
Heitzmann A., Helling C., Hoyer S., Isaak K.G., Kiss L.L., Lam K.W.F.,
Laskar J., Lecavelier des Etangs A., Magrin D., Maxted P.F.L., Mecina M.,
Mordasini Ch., Nascimbeni V., Olofsson G., Ottensamer R., Pagano I.,
Palle E., Peter G., Piazza D., Piotto G., Pollacco D., Queloz D.,
Ragazzoni R., Rando N., Rauer H., Ribas I., Santos N.C., Segransan D.,
Simon A.E., Stalport M., Szabo Gy.M., Thomas N., Udry S., Van Grootel V.,
Venturini J., Villaver E., Walton N.A.
<Astron. Astrophys. 685, A63 (2024)>
=2024A&A...685A..63A 2024A&A...685A..63A (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ; Optical
Keywords: planets and satellites: individual: WASP-12 b -
planets and satellites: interiors
Abstract:
Ultra-hot Jupiters present a unique opportunity to understand the
physics and chemistry of planets, their atmospheres, and interiors at
extreme conditions. WASP-12 b stands out as an archetype of this class
of exoplanets, with a close-in orbit around its star that results in
intense stellar irradiation and tidal effects. We performed
comprehensive analyses of the transits, occultations, and phase curves
of WASP-12b by combining new CHEOPS observations with previous TESS
and Spitzer data. The planet is modeled as a triaxial ellipsoid
parameterized by the second-order fluid Love number of the planet,
h2, which quantifies its radial deformation and provides insight
into the interior structure. We measure the tidal deformation of
WASP-12b and estimate a Love number of h2=1.55-0.49+0.45 (at
3.2σ) from its phase curve. We measure occultation depths of
333±24ppm and 493±29ppm in the CHEOPS and TESS bands,
respectively, while the nightside fluxes are consistent with zero, and
also marginal eastward phase offsets. Our modeling of the dayside
emission spectrum indicates that CHEOPS and TESS probe similar
pressure levels in the atmosphere at a temperature of ∼2900K. We also
estimate low geometric albedos of Ag=0.086±0.017 and
Ag=0.01±0.023 in the CHEOPS and TESS passbands, respectively which
suggest an absence of reflective clouds in the high-temperature
dayside of the planet. The CHEOPS occultations do not show strong
evidence for variability in the dayside atmosphere of the planet at
the median occultation depth precision of 120ppm attained. Finally,
combining the new CHEOPS timings with previous measurements refines
the precision of the orbital decay rate by 12% to a value of
∼30.23±0.82ms/yr, resulting in a modified stellar tidal quality
factor of Q'*=1.70±0.14x10.
Description:
CHEOPS WASP-12: transits, occultations, and a phase curve of the planet.
We obtained 47 visits of WASP-12 spanning 3 observation seasons
between 2022-11-02 and 2022-12-24 using CHEOPS as part of the
Guaranteed Time Observations. The visits, identified by unique file
keys, consist of 21 transits, 25 occultations, and half of a phase
curve of WASP-12 b, all taken at an exposure time of 60s.
Objects:
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RA (2000) DE Designation(s)
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06 30 32.79 +29 40 20.16 WASP-12 = TOI-1725
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
list.dat 42 47 List of curve files
lc/* . 47 Individual light curves
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 30 A30 --- Title Title of the file
32- 42 A11 --- FileName Name of the curve file in subdirectory lc
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Byte-by-byte Description of file: lc/*
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
3- 16 F14.6 d Time Time TDB (BJD)
18- 25 F8.6 --- Flux Flux
27- 34 F8.6 --- e_Flux Flux error
36- 43 E8.6 --- bg Background
45- 54 F10.6 deg RollAngle Spacecraft Roll angle
56- 64 F9.6 --- deltaT thermFront2 temperature
66- 74 E9.6 pix Xoff X offset
76- 84 E9.6 pix Yoff Y offset
86- 88 A3 --- Obstype Observation type (occ/tra/PC)
90- 97 F8.6 --- detFlux Detrended flux
99-106 F8.6 --- bwbrErr Enhanced flux error
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Acknowledgements:
Babatunde Akinsanmi, tunde.akinsanmi(at)unige.ch
(End) Patricia Vannier [CDS] 12-Feb-2024