J/A+A/669/A64 55 Cancri e occultation with CHEOPS (Demory+, 2023)
55 Cancri e's occultation captured with CHEOPS.
Demory B.-O., Sulis S., Meier Valdes E., Delrez L., Brandeker A., Billot N.,
Fortier A., Hoyer S., Sousa S.G., Heng K., Lendl M., Krenn A., Morris B.M.,
Patel J.A., Alibert Y., Alonso R., Anglada G., Barczy T., Barrado D.,
Barros S.C.C., Baumjohann W., Beck M., Beck T., Benz W., Bonfils X.,
Broeg C., Buder M., Cabrera J., Charnoz S., Collier Cameron A., Cottard H.,
Csizmadia Sz., Davies M.B., Deleuil M., Demangeon O.D.S., Ehrenreich D.,
Erikson A., Fossati L., Fridlund M., Gandolfi D., Gillon M., Guedel M.,
Isaak K.G., Kiss L.L., Laskar J., Lecavelier des Etangs A., Lovis C.,
Luntzer A., Magrin D., Marafatto L., Maxted P.F.L., Nascimbeni V.,
Olofsson G., Ottensamer R., Pagano I., Palle E., Peter G., Piotto G.,
Pollacco D., Queloz D., Ragazzoni R., Rando N., Ratti F., Rauer H.,
Ribas I., Santos N.C., Scandariato G., Segransan D., Simon A.E.,
Smith A.M.S., Steller M., Szabo Gy.M., Thomas N., Udry S., Van Grootel V.,
Walton N.A.
<Astron. Astrophys. 669, A64 (2023)>
=2023A&A...669A..64D 2023A&A...669A..64D (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ; Optical
Keywords: planets and satellites: individual: 55 Cancri e -
techniques: photometric - methods: observational
Abstract:
Past occultation and phase-curve observations of the ultra-short
period super-Earth 55 Cnc e obtained at visible and infrared
wavelengths have been challenging to reconcile with a planetary
reflection and emission model. In this study, we analyse a set of 41
occultations obtained over a two-year timespan with the CHEOPS
satellite. We report the detection of 55 Cnc e's occultation with an
average depth of 12±3 ppm. We derive a corresponding 2-sigma upper
limit on the geometric albedo of Ag<0.55 once decontaminated from
the thermal emission measured by Spitzer at 4.5 microns. CHEOPS's
photometric performance enables for the first time the detection of
individual occultations of this super-Earth in the visible and
identifies short-timescale photometric corrugations likely induced by
stellar granulation. We also find a clear 47.3-day sinusoidal pattern
in the time-dependent occultation depths that we are unable to relate
to stellar noise, nor instrumental systematics but whose planetary
origin could be tested with upcoming JWST occultation observations of
this iconic super-Earth.
Description:
We present CHEOPS photometry of 55 Cancri containing ten occultations.
raw.txt contains the raw photometric time-series with detrending
variables. detrended.txt contains the detrended photometric
time-series. Raw data can be obtained from the CHEOPS data archive:
https://cheops-archive.astro.unige.ch/archive_browser/
Objects:
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RA (2000) DE Designation(s)
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08 52 35.81 +28 19 50.95 55 Cancri = rho01 Cnc
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
raw.dat 175 10941 55 Cancri CHEOPS raw photometric time-series
with detrending variables
detrend.dat 63 10941 55 Cancri CHEOPS detrended photometric time-series
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Byte-by-byte Description of file: raw.dat
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Bytes Format Units Label Explanations
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5- 25 F21.16 d Time Time (BJD-2450000) (TDB)
33- 50 F18.16 --- Flux Normalised raw flux
58- 75 F18.16 --- e_Flux 1-sigma uncertainty in normalised flux
83-100 F18.16 --- xpos Normalised x-centroid position
108-125 F18.16 --- ypos Normalised y-centroid position
133-150 F18.16 rad roll Roll angle
158-175 F18.16 --- bkg Normalised Background
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Byte-by-byte Description of file: detrend.dat
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Bytes Format Units Label Explanations
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8- 15 F8.6 d dT Time from eclipse center
21- 31 F11.6 d Time Time (BJD-2450000) (TDB)
40- 47 F8.6 --- Flux Normalised detrended flux
56- 63 F8.6 --- e_Flux 1-sigma uncertainty in normalised detrended flux
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Acknowledgements:
Brice-Olivier Demory, brice.demory(at)unibe.ch
(End) Patricia Vannier [CDS] 21-Oct-2022