The atmosphere and architecture of WASP-189 b probed by its CHEOPS phase curve
Artikel i vetenskaplig tidskrift, 2022

Context. Gas giants orbiting close to hot and massive early-type stars can reach dayside temperatures that are comparable to those of the coldest stars. These 'ultra-hot Jupiters' have atmospheres made of ions and atomic species from molecular dissociation and feature strong day-to-night temperature gradients. Photometric observations at different orbital phases provide insights on the planet's atmospheric properties. Aims. We aim to analyse the photometric observations of WASP-189 acquired with the Characterising Exoplanet Satellite (CHEOPS) to derive constraints on the system architecture and the planetary atmosphere. Methods. We implemented a light-curve model suited for an asymmetric transit shape caused by the gravity-darkened photosphere of the fast-rotating host star. We also modelled the reflective and thermal components of the planetary flux, the effect of stellar oblateness and light-travel time on transit-eclipse timings, the stellar activity, and CHEOPS systematics. Results. From the asymmetric transit, we measure the size of the ultra-hot Jupiter WASP-189 b, R-p = 1.600(-0.016)(+0.017)R(J), with a precision of 1%, and the true orbital obliquity of the planetary system, Psi(P) = 89.6 +/- 1.2 deg (polar orbit). We detect no significant hotspot offset from the phase curve and obtain an eclipse depth of delta ecl = 96.5(-5.9)(+4).(5) ppm, from which we derive an upper limit on the geometric albedo: A(g) < 0.48. We also find that the eclipse depth can only be explained by thermal emission alone in the case of extremely inefficient energy redistribution. Finally, we attribute the photometric variability to the stellar rotation, either through superficial inhomogeneities or resonance couplings between the convective core and the radiative envelope. Conclusions. Based on the derived system architecture, we predict the eclipse depth in the upcoming Transiting Exoplanet Survey Satellite (TESS) observations to be up to similar to 165 ppm. High-precision detection of the eclipse in both CHEOPS and TESS passbands might help disentangle reflective and thermal contributions. We also expect the right ascension of the ascending node of the orbit to precess due to the perturbations induced by the stellar quadrupole moment J(2) (oblateness).

planets and satellites: atmospheres

techniques: photometric

planets and satellites: individual: WASP-189 b

Författare

A. Deline

Université de Genève

M. J. Hooton

Universität Bern

M. Lendl

Université de Genève

B. Morris

Universität Bern

S. Salmon

Université de Genève

G. Olofsson

Stockholms universitet

C. Broeg

Universität Bern

D. Ehrenreich

Université de Genève

M. Beck

Université de Genève

A. Brandeker

Stockholms universitet

S. Hoyer

Aix-Marseille Université

S. Sulis

Aix-Marseille Université

V. Van Grootel

Universite de Liège

V Bourrier

Université de Genève

O. Demangeon

Universidade do Porto

B-O Demory

Universität Bern

K. Heng

Ludwig-Maximilians-Universität München (LMU)

Universität Bern

The University of Warwick

H. Parviainen

Universidad de la Laguna

Instituto de Astrofísica de Canarias

L. M. Serrano

Universita degli Studi di Torino

V Singh

Osservatorio Astronomico di Padova

A. Bonfanti

Österreichische Akademie der Wissenschaften

L. Fossati

Österreichische Akademie der Wissenschaften

D. Kitzmann

Universität Bern

S. G. Sousa

Universidade do Porto

T. G. Wilson

University of St Andrews

Y. Alibert

Universität Bern

R. Alonso

Universidad de la Laguna

Instituto de Astrofísica de Canarias

G. Anglada

Consejo Superior de Investigaciones Científicas (CSIC)

T. Barczy

Admatis

D. Barrado Navascues

Centro de Astrobiología (INTA-CSIC)

S. C. C. Barros

Universidade do Porto

W. Baumjohann

Österreichische Akademie der Wissenschaften

T. Beck

Universität Bern

A. Bekkelien

Université de Genève

W. Benz

Universität Bern

N. Billot

Université de Genève

X. Bonfils

Université Grenoble Alpes

J. Cabrera

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

S. Charnoz

Université Paris Descartes

A. Collier Cameron

University of St Andrews

C. Corral van Damme

Europeiska rymdorganisationen (ESA)

Sz Csizmadia

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

M. B. Davies

Lunds universitet

M. Deleuil

Aix-Marseille Université

L. Delrez

Universite de Liège

T. de Roche

Universität Bern

A. Erikson

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

A. Fortier

Universität Bern

Malcolm Fridlund

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

D. Futyan

Université de Genève

D. Gandolfi

Universita degli Studi di Torino

M. Gillon

Universite de Liège

M. Gudel

Universität Wien

P. Gutermann

Aix-Marseille Université

Institut National des Sciences de l'Univers

J. Hasiba

Österreichische Akademie der Wissenschaften

K. G. Isaak

Europeiska rymdorganisationen (ESA)

L. Kiss

Magyar Tudomanyos Akademia

J. Laskar

Sorbonne Université

A. Lecavelier des Etangs

Université Pierre et Marie Curie (UPMC)

C. Lovis

Université de Genève

D. Magrin

Osservatorio Astronomico di Padova

P. F. L. Maxted

Keele University

M. Munari

Osservatorio Astrofisico di Catania

V Nascimbeni

Osservatorio Astronomico di Padova

R. Ottensamer

Universität Wien

I Pagano

Osservatorio Astrofisico di Catania

E. Palle

Instituto de Astrofísica de Canarias

G. Peter

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

G. Piotto

Università di Padova

Osservatorio Astronomico di Padova

D. Pollacco

The University of Warwick

D. Queloz

University of Cambridge

Eidgenössische Technische Hochschule Zürich (ETH)

R. Ragazzoni

Università di Padova

Osservatorio Astronomico di Padova

N. Rando

Europeiska rymdorganisationen (ESA)

H. Rauer

Technische Universität Berlin

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

Freie Universität Berlin

I Ribas

Institut d'Estudis Espacials de Catalunya (IEEC)

Consejo Superior de Investigaciones Científicas (CSIC)

N. C. Santos

Universidade do Porto

G. Scandariato

Osservatorio Astrofisico di Catania

D. Segransan

Université de Genève

A. E. Simon

Universität Bern

A. M. S. Smith

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

M. Steller

Österreichische Akademie der Wissenschaften

Gy M. Szabo

Eötvös Loránd University (ELTE)

N. Thomas

Universität Bern

S. Udry

Université de Genève

I Walter

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

N. Walton

University of Cambridge

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 659 A74

Ämneskategorier

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik

Den kondenserade materiens fysik

DOI

10.1051/0004-6361/202142400

Mer information

Senast uppdaterat

2022-03-31