J/A+A/643/A94 CHEOPS WASP-189 b transit light curve (Lendl+, 2020)
The hot dayside and asymmetric transit of WASP-189 b seen by CHEOPS.
Lendl M., Csizmadia Sz., Deline A., Fossati L., Kitzmann D., Heng S.,
Hoyer K., Salmon S., Benz W., Broeg C., Ehrenreich D., Fortier A.,
Queloz D., Bonfanti A., Brandeker A., Collier Cameron A., Delrez L.,
Garcia Munoz A., Hooton M.J., Maxted P.F.L., Morris B.M., Van Grootel V.,
Wilson T.G., Alibert Y., Alonso R., Asquier J., Bandy T., Barczy T.,
Barrado D., Barros S.C.C., Baumjohann W., Beck M., Beck T., Bekkelien A.,
Bergomi M., Billot N., Biondi F., Bonfils X., Bourrier V., Busch M.-D.,
Cabrera J., Cessa V., Charnoz S., Chazelas B., Corral Van Damme C.,
Davies M.B., Deleuil M., Demangeon O.D.S., Demory B.-O., Erikson A.,
Farinato J., Fridlund M., Futyan D., Gandolfi D., Gillon M., Guterman P.,
Hasiba J., Hernandez E., Isaak K.G., Kiss L., Kuntzer T.,
Lecavelier des Etangs A., Lueftinger T., Laskar J., Lovis C., Magrin D.,
Malvasio L., Marafatto L., Michaelis H., Munari M., Nascimbeni V.,
Olofsson G., Ottacher H., Ottensamer R., Pagano I., Palle E., Peter G.,
Piazza D., Piotto G., Pollacco D., Ratti F., Rauer H., Ragazzoni R.,
Rando N., Ribas I., Rieder M., Rohlfs R., Safa F., Santos N.C.,
Scandariato G., Segransan D., Simon A.E., Singh V., Smith A.M.S.,
Sordet M., Sousa S.G., Steller M., Szabo Gy.M., Thomas N., Tschentscher M.,
Udry S., Viotto V., Walter I., Walton N.A., Wildi F., Wolter D.
<Astron. Astrophys. 643, A94 (2020)>
=2020A&A...643A..94L 2020A&A...643A..94L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry
Keywords: techniques: photometric - planets and satellites: atmospheres -
planets and satellites: individual: WASP-189 b
Abstract:
CHEOPS (CHaracterising ExOPlanets Satellite), launched in December
2019, is a space mission dedicated to exoplanet follow-up with the
capacity to perform photometric measurements at the20 ppm level. As
CHEOPS observes in a broad optical passband, it can be used provide
insights on the reflected light from exoplanets, and constrain the
short-wavelength thermal emission for the hottest of planets through
the observation of occultations and phase curves. We here report the
first observation of an occultation by CHEOPS: that of the hot Jupiter
WASP-189b, a M∼2MJ planet orbiting an A-type star. We detect the
occultation of WASP-189b at high significance in individual
measurements, and derive an occultation depth of dF=87.9±4.3 ppm
based on four occultations. We compare this measurement to model
predictions and find that, when assuming inefficient heat
redistribution, they are consistent with an unreflective atmosphere,
heated to a temperature of 3435±27K.
We furthermore present two transits of WASP-189b observed by CHEOPS.
These transits have an asymmetric shape that we attribute to gravity
darkening of the host star due to its high rotation rate. We use these
measurements to refine the planetary parameters, finding a ∼25% deeper
transit compared to the discovery paper and updating the radius of
WASP-189b to 1.619±0.021RJ. We further measure the projected
orbital obliquity to be lambda=86.4(+2.9,-4.4)deg, a value in good
agreement with a previous measurement from spectroscopic observations,
and derive a true obliquity of Psi=85.4±4.3deg.
Finally, we provide reference values for the photometric precision
attained by the CHEOPS satellite: for the V=6.6 mag star, and using a
1-hour binning, we obtain a residual RMS between 10 and 17ppm on the
individual light curves, and 5.7ppm when combining four visits.
Description:
We present photometric light curves observed by CHEOPS, containing
four occultations and two transits of WASP-189b.
Objects:
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RA (2000) DE Designation(s)
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15 02 44.87 -03 01 53.0 WASP-189 = HD 133112
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 61 5113 CHEOPS photometry of WASP-189
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 F11.6 d BJD Barycentric Julian Date (BJD-2450000)
13- 20 F8.6 --- Flux Normalized Flux
22- 29 F8.6 --- e_Flux Normalized Flux error
31- 36 F6.3 pix xshift Pixel shift in x-direction
38- 43 F6.3 pix yshift Pixel shift in y-direction
45- 51 F7.3 deg roll Spacecraft roll angle
53- 61 F9.7 --- conta Relative contamination
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Acknowledgements:
Monika Lendl, monika.lendl(at)unige.ch
(End) Patricia Vannier [CDS] 20-Sep-2020