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.

Planets and satellites: Individual: 55 Cnc e

Stars: Individual: 55 Cnc

Techniques: Photometric

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

Ludwig-Maximilians-Universität München (LMU)

Universität Bern

The University of Warwick

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

Instituto de Astrofísica de Canarias

Universidad de la Laguna

G. Anglada

Consejo Superior de Investigaciones Científicas (CSIC)

Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)

J. Asquier

Europeiska rymdorganisationen (ESA)

T. Bárczy

Admatis

D. Barrado Navascues

Europeiska rymdorganisationen (ESA)

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

Europeiska rymdorganisationen (ESA)

S. Hoyer

Laboratoire d'Astrophysique de Marseille

K. Isaak

Europeiska rymdorganisationen (ESA)

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

Istituto nazionale di astrofisica (INAF)

Università di Padova

Don L. Pollacco

The University of Warwick

D. Queloz

University of Cambridge

Eidgenössische Technische Hochschule Zürich (ETH)

R. Ragazzoni

Istituto nazionale di astrofisica (INAF)

Università di Padova

N. Rando

Europeiska rymdorganisationen (ESA)

H. Rauer

Freie Universität Berlin

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

Technische Universität Berlin

I. Ribas

Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)

Consejo Superior de Investigaciones Científicas (CSIC)

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 A112

Ämneskategorier (SSIF 2011)

Astronomi, astrofysik och kosmologi

DOI

10.1051/0004-6361/202346050

Mer information

Senast uppdaterat

2025-04-23