Investigating the visible phase-curve variability of 55 Cnc e
Artikel i vetenskaplig tidskrift, 2023
Context. 55 Cnc e is an ultra-short period super-Earth transiting a Sun-like star. Previous observations in the optical range detected a time-variable flux modulation that is phased with the planetary orbital period, whose amplitude is too large to be explained by reflected light and thermal emission alone. Aims. The goal of the study is to investigate the origin of the variability and timescale of the phase-curve modulation in 55 Cnc e. To this end, we used the CHaracterising ExOPlanet Satellite (CHEOPS), whose exquisite photometric precision provides an opportunity to characterise minute changes in the phase curve from one orbit to the next. Methods. CHEOPS observed 29 individual visits of 55 Cnc e between March 2020 and February 2022. Based on these observations, we investigated the different processes that could be at the origin of the observed modulation. In particular, we built a toy model to assess whether a circumstellar torus of dust driven by radiation pressure and gravity might match the observed flux variability timescale. Results. We find that the phase-curve amplitude and peak offset of 55 Cnc e do vary between visits. The sublimation timescales of selected dust species reveal that silicates expected in an Earth-like mantle would not survive long enough to explain the observed phase-curve modulation. We find that silicon carbide, quartz, and graphite are plausible candidates for the circumstellar torus composition because their sublimation timescales are long. Conclusions. The extensive CHEOPS observations confirm that the phase-curve amplitude and offset vary in time. We find that dust could provide the grey opacity source required to match the observations. However, the data at hand do not provide evidence that circumstellar material with a variable grain mass per unit area causes the observed variability. Future observations with the James Webb Space Telescope (JWST) promise exciting insights into this iconic super-Earth.
Techniques: Photometric
Planets and satellites: Individual: 55 Cnc e
Stars: Individual: 55 Cnc
Författare
E. Meier Valdes
Universität Bern
Brett M. Morris
Space Telescope Science Institute (STScI)
B.O. Demory
Universität Bern
A. Brandeker
Stockholms universitet
D. Kitzmann
Universität Bern
W. Benz
Universität Bern
A. Deline
Université de Genève
H.-G. Florén
Stockholms universitet
S.G. Sousa
Universidade do Porto
V. Bourrier
Université de Genève
V. Singh
Istituto nazionale di astrofisica (INAF)
Kevin Heng
The University of Warwick
Universität Bern
Ludwig-Maximilians-Universität München (LMU)
Antoine Strugarek
Université Paris-Saclay
D. J. Bower
Universität Bern
N. Jäggi
Universität Bern
L. Carone
Institut fur Weltraumforschung
M. Lendl
Université de Genève
K. Jones
Universität Bern
A. V. Oza
California Institute of Technology (Caltech)
O. Demangeon
Universidade do Porto
Y. Alibert
Universität Bern
R. Alonso
Universidad de la Laguna
Instituto de Astrofísica de Canarias
G. Anglada
Institut d'Estudis Espacials de Catalunya (IEEC)
Institut de Ciències de l'Espai (ICE) - CSIC
J. Asquier
European Space Research and Technology Centre (ESA ESTEC)
T. Bárczy
Admatis
D. Barrado Navascues
European Space Astronomy Centre (ESAC)
S.C.C. Barros
Universidade do Porto
W. Baumjohann
Institut fur Weltraumforschung
M. Beck
Université de Genève
T. Beck
Universität Bern
N. Billot
Université de Genève
X. Bonfils
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
L. Borsato
Istituto nazionale di astrofisica (INAF)
C. Broeg
Universität Bern
J. Cabrera
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
S. Charnoz
Institut de Physique du Globe de Paris
A. Collier Cameron
University of St Andrews
Szilard Csizmadia
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
P. E. Cubillos
Institut fur Weltraumforschung
Istituto nazionale di astrofisica (INAF)
Melvyn B. Davies
Lunds universitet
M. Deleuil
Laboratoire d'Astrophysique de Marseille
L. Delrez
Universite de Liège
D. Ehrenreich
Université de Genève
Anders Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Fortier
Universität Bern
L. Fossati
Institut fur Weltraumforschung
Malcolm Fridlund
Universiteit Leiden
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
D. Gandolfi
Universita degli Studi di Torino
Michaël Gillon
Universite de Liège
M. Gudel
Universität Wien
Maximilian N. Günther
European Space Research and Technology Centre (ESA ESTEC)
S. Hoyer
Laboratoire d'Astrophysique de Marseille
K. Isaak
European Space Research and Technology Centre (ESA ESTEC)
L. Kiss
Eötvös Loránd University (ELTE)
Magyar Tudomanyos Akademia
J. Laskar
Observatoire de Paris
A. L. des Etangs
Institut d 'Astrophysique de Paris
C. Lovis
Université de Genève
D. Magrin
Istituto nazionale di astrofisica (INAF)
P. Maxted
Keele University
C. Mordasini
Universität Bern
Valerio Nascimbeni
Istituto nazionale di astrofisica (INAF)
G. Olofsson
Stockholms universitet
R. Ottensamer
Universität Wien
I. Pagano
Istituto nazionale di astrofisica (INAF)
Enric Palle
Instituto de Astrofísica de Canarias
G. Peter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Giampaolo P. Piotto
Università di Padova
Istituto nazionale di astrofisica (INAF)
Don L. Pollacco
The University of Warwick
D. Queloz
Eidgenössische Technische Hochschule Zürich (ETH)
University of Cambridge
R. Ragazzoni
Istituto nazionale di astrofisica (INAF)
Università di Padova
N. Rando
European Space Research and Technology Centre (ESA ESTEC)
H. Rauer
Freie Universität Berlin
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Technische Universität Berlin
I. Ribas
Institut de Ciències de l'Espai (ICE) - CSIC
Institut d'Estudis Espacials de Catalunya (IEEC)
N. C. Santos
Universidade do Porto
M. Sarajlic
Universität Bern
Gaetano Scandariato
Istituto nazionale di astrofisica (INAF)
D. Segransan
Université de Genève
D. Sicilia
Istituto nazionale di astrofisica (INAF)
A.E. Simon
Universität Bern
A. M.S. Smith
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Manfred B. Steller
Institut fur Weltraumforschung
G.M. Szabó
Eötvös Loránd University (ELTE)
Nicolas Thomas
Universität Bern
S. Udry
Université de Genève
B. Ulmer
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
V. Van Grootel
Universite de Liège
J. Venturini
Université de Genève
N. A. Walton
University of Cambridge
T.G. Wilson
University of St Andrews
D. Wolter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 677 A112Ämneskategorier
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/202346050