CHEOPS precision phase curve of the Super-Earth 55 Cancri e
Journal article, 2021
Context. 55 Cnc e is a transiting super-Earth (radius 1.88 R-circle plus and mass 8 M-circle plus) orbiting a G8V host star on a 17-h orbit. Spitzer observations of the planet's phase curve at 4.5 mu m revealed a time-varying occultation depth, and MOST optical observations are consistent with a time-varying phase curve amplitude and phase offset of maximum light. Both broadband and high-resolution spectroscopic analyses are consistent with either a high mean molecular weight atmosphere or no atmosphere for planet e. A long-term photometric monitoring campaign on an independent optical telescope is needed to probe the variability in this system. Aims. We seek to measure the phase variations of 55 Cnc e with a broadband optical filter with the 30 cm effective aperture space telescope CHEOPS and explore how the precision photometry narrows down the range of possible scenarios. Methods. We observed 55 Cnc for 1.6 orbital phases in March of 2020. We designed a phase curve detrending toolkit for CHEOPS photometry which allowed us to study the underlying flux variations in the 55 Cnc system. Results. We detected a phase variation with a full-amplitude of 72 +/- 7 ppm, but did not detect a significant secondary eclipse of the planet. The shape of the phase variation resembles that of a piecewise-Lambertian; however, the non-detection of the planetary secondary eclipse, and the large amplitude of the variations exclude reflection from the planetary surface as a possible origin of the observed phase variations. They are also likely incompatible with magnetospheric interactions between the star and planet, but may imply that circumplanetary or circumstellar material modulate the flux of the system. Conclusions. This year, further precision photometry of 55 Cnc from CHEOPS will measure variations in the phase curve amplitude and shape over time.
methods: observational
instrumentation: photometers
planets and satellites: atmospheres
techniques: photometric
planets and satellites: individual: 55 Cnc e
stars: individual: 55 Cnc
Author
B. M. Morris
University of Bern
L. Delrez
University of Geneva
University of Liège
A. Brandeker
Stockholm University
A. C. Cameron
University of St Andrews
A. E. Simon
University of Bern
D. Futyan
University of Geneva
G. Olofsson
Stockholm University
S. Hoyer
Aix Marseille University
A. Fortier
University of Bern
B-O Demory
University of Bern
M. Lendl
University of Geneva
T. G. Wilson
University of St Andrews
M. Oshagh
University of La Laguna
Instituto de Astrofísica de Canarias
K. Heng
University of Bern
D. Ehrenreich
University of Geneva
S. Sulis
Aix Marseille University
Y. Alibert
University of Bern
R. Alonso
Instituto de Astrofísica de Canarias
University of La Laguna
G. Anglada Escude
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
Spanish National Research Council (CSIC)
D. Barrado
Spanish National Research Council (CSIC)
S. C. C. Barros
University of Porto
W. Baumjohann
Austrian Academy of Sciences
M. Beck
University of Geneva
T. Beck
University of Bern
A. Bekkelien
University of Geneva
W. Benz
University of Bern
M. Bergomi
Istituto nazionale di astrofisica (INAF)
N. Billot
University of Geneva
X. Bonfils
Grenoble Alpes University
V Bourrier
University of Geneva
C. Broeg
University of Bern
T. Barczy
Admatis
J. Cabrera
German Aerospace Center (DLR)
S. Charnoz
Paris Descartes University
M. B. Davies
Lund University
D. De Miguel Ferreras
Airbus Group
M. Deleuil
Aix Marseille University
A. Deline
University of Geneva
O. D. S. Demangeon
University of Porto
A. Erikson
German Aerospace Center (DLR)
H. G. Floren
Stockholm University
L. Fossati
Austrian Academy of Sciences
Malcolm Fridlund
Leiden University
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
D. Gandolfi
University of Turin
A. Garcia Munoz
Technische Universität Berlin
M. Gillon
University of Liège
M. Guedel
University of Vienna
P. Guterman
Aix Marseille University
Institut National des Sciences de l'Univers
K. Isaak
European Space Agency (ESA)
L. Kiss
The University of Sydney
Eötvös Loránd University (ELTE)
Hungarian Academy of Sciences
J. Laskar
Université Paris PSL
A. Lecavelier des Etangs
Pierre and Marie Curie University (UPMC)
M. Lieder
German Aerospace Center (DLR)
C. Lovis
University of Geneva
D. Magrin
Istituto nazionale di astrofisica (INAF)
P. F. L. Maxted
Keele University
V Nascimbeni
Istituto nazionale di astrofisica (INAF)
R. Ottensamer
University of Vienna
I Pagano
Istituto nazionale di astrofisica (INAF)
E. Palle
Instituto de Astrofísica de Canarias
University of La Laguna
G. Peter
German Aerospace Center (DLR)
G. Piotto
Istituto nazionale di astrofisica (INAF)
University of Padua
A. Pizarro Rubio
Airbus Group
D. Pollacco
The University of Warwick
F. J. Pozuelos
University of Liège
D. Queloz
University of Geneva
University of Cambridge
R. Ragazzoni
University of Padua
Istituto nazionale di astrofisica (INAF)
N. Rando
European Space Agency (ESA)
H. Rauer
Technische Universität Berlin
Freie Universität Berlin
German Aerospace Center (DLR)
I Ribas
Spanish National Research Council (CSIC)
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
N. C. Santos
University of Porto
G. Scandariato
Istituto nazionale di astrofisica (INAF)
A. M. S. Smith
German Aerospace Center (DLR)
S. G. Sousa
University of Porto
M. Steller
Austrian Academy of Sciences
Gy M. Szabo
Eötvös Loránd University (ELTE)
D. Segransan
University of Geneva
N. Thomas
University of Bern
S. Udry
University of Geneva
B. Ulmer
Ingenieurbüro Ulmer
V. Van Grootel
University of Liège
N. A. Walton
University of Cambridge
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 653 A173Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Other Physics Topics
DOI
10.1051/0004-6361/202140892