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.

techniques: photometric

planets and satellites: individual: 55 Cnc e

instrumentation: photometers

methods: observational

planets and satellites: atmospheres

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

Instituto de Astrofísica de Canarias

University of La Laguna

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

Institute of Space Studies of Catalonia (IEEC)

Spanish National Research Council (CSIC)

D. Barrado

Spanish Astrobiology Center (INTA-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

Osservatorio Astronomico di Padova

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 DS Spain

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

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Leiden University

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 Research and Technology Centre (ESA ESTEC)

L. Kiss

Hungarian Academy of Sciences

The University of Sydney

Eötvös Loránd University (ELTE)

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

Osservatorio Astronomico di Padova

P. F. L. Maxted

Keele University

V Nascimbeni

Osservatorio Astronomico di Padova

R. Ottensamer

University of Vienna

I Pagano

Osservatorio Astrofisico di Catania

E. Palle

University of La Laguna

Instituto de Astrofísica de Canarias

G. Peter

German Aerospace Center (DLR)

G. Piotto

University of Padua

Osservatorio Astronomico di Padova

A. Pizarro Rubio

Airbus DS Spain

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

Osservatorio Astronomico di Padova

N. Rando

European Space Agency (ESA)

H. Rauer

Freie Universität Berlin

Technische Universität Berlin

German Aerospace Center (DLR)

I Ribas

Spanish National Research Council (CSIC)

Institute of Space Studies of Catalonia (IEEC)

N. C. Santos

University of Porto

G. Scandariato

Osservatorio Astrofisico di Catania

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 A173

Subject Categories

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

Other Physics Topics

DOI

10.1051/0004-6361/202140892

More information

Latest update

10/14/2021