CHEOPS and TESS view of the ultra-short-period super-Earth TOI-561 b
Artikel i vetenskaplig tidskrift, 2023
Context. Ultra-short-period planets (USPs) are a unique class of super-Earths with an orbital period of less than a day, and hence they are subject to intense radiation from their host star. These planets cannot retain a primordial H/He atmosphere, and most of them are indeed consistent with being bare rocky cores. A few USPs, however, show evidence for a heavyweight envelope, which could be a water layer resilient to evaporation or a secondary metal-rich atmosphere sustained by outgassing of the molten volcanic surface. Much thus remains to be learned about the nature and formation of USPs. Aims. The prime goal of the present work is to refine the bulk planetary properties of the recently discovered TOI-561 b through the study of its transits and occultations. This is crucial in order to understand the internal structure of this USP and to assess the presence of an atmosphere. Methods. We obtained ultra-precise transit photometry of TOI-561 b with CHEOPS, and performed a joint analysis of these data along with three archival visits from CHEOPS and four TESS sectors. Results. Our analysis of TOI-561 b transit photometry put strong constraints on its properties. In particular, we restrict the uncertainties on the planetary radius at similar to 2% retrieving R-p = 1.42 +/- 0.02 R-circle plus. This result informs our internal structure modelling of the planet, which shows that the observations are consistent with a negligible H/He atmosphere; however, other lighter materials are required, in addition to a pure iron core and a silicate mantle, to explain the observed density. We find that this can be explained by the inclusion of a water layer in our model. Additionally, we ran a grid of forward models with a water-enriched atmosphere to explain the transit radius. We searched for variability in the measured R-p/R-star over time, which could trace changes in the structure of the planetary envelope. However, no temporal variations are recovered within the present data precision. In addition to the transit event, we tentatively detect an occultation signal in the TESS data with an eclipse depth L = 27.40(-11.35)(+10.87) ppm. We use models of outgassed atmospheres from the literature to explain this eclipse signal. We find that the thermal emission from the planet can mostly explain the observation. Based on this, we predict that near- to mid-infrared observations with the James Webb Space Telescope should be able to detect silicate species in the atmosphere of the planet. This could also reveal important clues about the planetary interior and help disentangle planet formation and evolution models.
planets and satellites: atmospheres
planets and satellites: composition
planets and satellites: individual: TOI-561 b
techniques: photometric
planets and satellites: terrestrial planets
Författare
J. A. Patel
Stockholms universitet
J. A. Egger
Universität Bern
T. G. Wilson
University of St Andrews
The University of Warwick
V. Bourrier
Université de Genève
L. Carone
Österreichische Akademie der Wissenschaften
M. Beck
Université de Genève
D. Ehrenreich
Université de Genève
S. G. Sousa
Universidade do Porto
W. Benz
Universität Bern
A. Brandeker
Stockholms universitet
A. Deline
Université de Genève
Y. Alibert
Universität Bern
K. W. F. Lam
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
M. Lendl
Université de Genève
R. Alonso
Universidad de la Laguna
Instituto de Astrofísica de Canarias
G. Anglada
Institut d'Estudis Espacials de Catalunya (IEEC)
Consejo Superior de Investigaciones Científicas (CSIC)
T. Barczy
Admatis
D. Barrado
Consejo Superior de Investigaciones Científicas (CSIC)
S. C. C. Barros
Universidade do Porto
W. Baumjohann
Österreichische Akademie der Wissenschaften
T. Beck
Universität Bern
N. Billot
Université de Genève
X. Bonfils
Université Grenoble Alpes
C. Broeg
Universität Bern
M. -d. Busch
Universität Bern
J. Cabrera
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
S. Charnoz
Université Paris Descartes
A. Collier Cameron
University of St Andrews
Sz. Csizmadia
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
M. B. Davies
Lunds universitet
M. Deleuil
Aix-Marseille Université
L. Delrez
Universite de Liège
O. D. S. Demangeon
Universidade do Porto
B. -o. Demory
Universität Bern
A. Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Fortier
Universität Bern
L. Fossati
Österreichische Akademie der Wissenschaften
Malcolm Fridlund
Universiteit Leiden
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
D. Gandolfi
Universita degli Studi di Torino
M. Gillon
Universite de Liège
M. Guedel
Universität Wien
K. Heng
The University of Warwick
Universität Bern
S. Hoyer
Aix-Marseille Université
K. G. Isaak
Europeiska rymdorganisationen (ESA)
L. L. Kiss
Magyar Tudomanyos Akademia
Eötvös Loránd University (ELTE)
E. Kopp
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
J. Laskar
Sorbonne Université
A. Lecavelier des Etangs
Université Pierre et Marie Curie (UPMC)
C. Lovis
Université de Genève
D. Magrin
Istituto nazionale di astrofisica (INAF)
P. F. L. Maxted
Keele University
V. Nascimbeni
Istituto nazionale di astrofisica (INAF)
G. Olofsson
Stockholms universitet
R. Ottensamer
Universität Wien
I. Pagano
Istituto nazionale di astrofisica (INAF)
E. Palle
Instituto de Astrofísica de Canarias
G. Peter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
G. Piotto
Università di Padova
Istituto nazionale di astrofisica (INAF)
D. Pollacco
The University of Warwick
D. Queloz
University of Cambridge
Eidgenössische Technische Hochschule Zürich (ETH)
R. Ragazzoni
Università di Padova
Istituto nazionale di astrofisica (INAF)
N. Rando
Europeiska rymdorganisationen (ESA)
F. Ratti
Europeiska rymdorganisationen (ESA)
H. Rauer
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Freie Universität Berlin
Technische 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
Istituto nazionale di astrofisica (INAF)
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
B. Ulmer
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
V. Van Grootel
Universite de Liège
V. Viotto
Istituto nazionale di astrofisica (INAF)
N. A. Walton
University of Cambridge
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 679 A92Satellitstudier av exoplaneters mångfald
Rymdstyrelsen (174/18), 2019-02-04 -- 2023-08-01.
Exoplaneter från rymden - CHEOPS och PLATO, ESA's nästa två rymdteleskop (fas 2)
Rymdstyrelsen (65/19), 2020-01-01 -- 2022-12-31.
Rymdstyrelsen (177/19), 2020-01-01 -- 2022-12-31.
Ämneskategorier
Astronomi, astrofysik och kosmologi
Annan fysik
DOI
10.1051/0004-6361/202244946