Six transiting planets and a chain of Laplace resonances in TOI-178
Artikel i vetenskaplig tidskrift, 2021
Determining the architecture of multi-planetary systems is one of the cornerstones of understanding planet formation and evolution. Resonant systems are especially important as the fragility of their orbital configuration ensures that no significant scattering or collisional event has taken place since the earliest formation phase when the parent protoplanetary disc was still present. In this context, TOI-178 has been the subject of particular attention since the first TESS observations hinted at the possible presence of a near 2:3:3 resonant chain. Here we report the results of observations from CHEOPS, ESPRESSO, NGTS, and SPECULOOS with the aim of deciphering the peculiar orbital architecture of the system. We show that TOI-178 harbours at least six planets in the super-Earth to mini-Neptune regimes, with radii ranging from 1.152 to 2.87 Earth radii and periods of 1.91, 3.24, 6.56, 9.96, 15.23, and 20.71 days. All planets but the innermost one form a 2:4:6:9:12 chain of Laplace resonances, and the planetary densities show important variations from planet to planet, jumping from 1.02 to 0.177 times the Earth's density between planets c and d. Using Bayesian interior structure retrieval models, we show that the amount of gas in the planets does not vary in a monotonous way, contrary to what one would expect from simple formation and evolution models and unlike other known systems in a chain of Laplace resonances. The brightness of TOI-178 (H = 8.76 mag, J = 9.37 mag, V = 11.95 mag) allows for a precise characterisation of its orbital architecture as well as of the physical nature of the six presently known transiting planets it harbours. The peculiar orbital configuration and the diversity in average density among the planets in the system will enable the study of interior planetary structures and atmospheric evolution, providing important clues on the formation of super-Earths and mini-Neptunes. -0.070 -0.13 -0.23 -0.061 +0.073 +0.14 +0.28 +0.055
Techniques: Photometric
Celestial mechanics
Planets and satellites: Detection
Techniques: Spectroscopic
Planets and satellites: Dynamical evolution and stability
Författare
A. Leleu
Université de Genève
Y. Alibert
Universität Bern
N.C. Hara
Université de Genève
M.J. Hooton
Universität Bern
T.G. Wilson
University of St Andrews
P. Robutel
Observatoire de Paris
J. B. Delisle
Université de Genève
J. Laskar
Observatoire de Paris
S. Hoyer
Laboratoire d'Astrophysique de Marseille
C. Lovis
Université de Genève
E. Bryant
The University of Warwick
E. Ducrot
Universite de Liège
J. Cabrera
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
L. Delrez
Université de Genève
J.S. Acton
University Of Leicester
V. Adibekyan
Universidade do Porto
R. Allart
Université de Genève
C. Allende Prieto
Instituto de Astrofísica de Canarias
R. Alonso
Instituto de Astrofísica de Canarias
D. Alves
Camino El Observatorio 1515
D.R. Anderson
The University of Warwick
D. Angerhausen
Eidgenössische Technische Hochschule Zürich (ETH)
G. Anglada Escude´
Institut de Ciències de l'Espai (ICE) - CSIC
J. Asquier
European Space Research and Technology Centre (ESA ESTEC)
D. Barrado
European Space Astronomy Centre (ESAC)
S.C.C. Barros
Universidade do Porto
W. Baumjohann
Institut fur Weltraumforschung
D. Bayliss
The University of Warwick
M. Beck
Université de Genève
T. Beck
Universität Bern
A. Bekkelien
Université de Genève
W. Benz
Universität Bern
N. Billot
Université de Genève
A. Bonfanti
Institut fur Weltraumforschung
X. Bonfils
Université Grenoble Alpes
F. Bouchy
Université de Genève
V. Bourrier
Université de Genève
G. Boue´
Observatoire de Paris
A. Brandeker
Stockholms universitet
C. Broeg
Universität Bern
M. Buder
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Burdanov
Universite de Liège
Matt Burleigh
University Of Leicester
T. Bárczy
Admatis
A.C. Cameron
University of St Andrews
S. Chamberlain
University Of Leicester
S. Charnoz
Université Paris Descartes
B. Cooke
The University of Warwick
C. Corral Van Damme
European Space Research and Technology Centre (ESA ESTEC)
A.C.M. Correia
Observatoire de Paris
S. Cristiani
Osservatorio Astronomico di Trieste
Mario Damasso
Istituto nazionale di astrofisica (INAF)
Melvyn B. Davies
Lunds universitet
M. Deleuil
Laboratoire d'Astrophysique de Marseille
O. Demangeon
Universidade do Porto
B.O. Demory
Universität Bern
P. Di Marcantonio
Osservatorio Astronomico di Trieste
G. Di Persio
Istituto nazionale di astrofisica (INAF)
X. Dumusque
Université de Genève
D. Ehrenreich
Université de Genève
Anders Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
P. Figueira
Universidade do Porto
A. Fortier
Universität Bern
L. Fossati
Institut fur Weltraumforschung
Malcolm Fridlund
Universiteit Leiden
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
D. Futyan
Université de Genève
D. Gandolfi
Universita degli Studi di Torino
A. Garcia´ Muno&tild;z
Technische Universität Berlin
L.J. Garcia
Universite de Liège
S. Gill
The University of Warwick
E. Gillen
Queen Mary University of London
Michaël Gillon
Universite de Liège
M.R. Goad
University Of Leicester
J.I. Gonza´lez Herna´ndez
Instituto de Astrofísica de Canarias
M. Guedel
Universität Wien
M.N. Gu¨nther
Massachusetts Institute of Technology (MIT)
J. Haldemann
Universität Bern
B. Henderson
University Of Leicester
Kevin Heng
Universität Bern
A.E. Hogan
University Of Leicester
K. Isaak
European Space Research and Technology Centre (ESA ESTEC)
Emmanuel Jehin
Universite de Liège
J.S. Jenkins
Universidad de Chile (UCH)
A. Jorda´n
Universidad Adolfo Ibanez
L. Kiss
Magyar Tudomanyos Akademia
M. H. Kristiansen
Brorfelde Observatory
K. W.F. Lam
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
B. Lavie
Université de Genève
A. L. des Etangs
Institut d 'Astrophysique de Paris
M. Lendl
Université de Genève
J. Lillo-Box
European Space Astronomy Centre (ESAC)
G. Lo Curto
European Southern Observatory Santiago
D. Magrin
Istituto nazionale di astrofisica (INAF)
C.J.A.P. Martins
Universidade do Porto
P. Maxted
Keele University
J. McCormac
The University of Warwick
A. Mehner
European Southern Observatory Santiago
G. Micela
Istituto nazionale di astrofisica (INAF)
P. Molaro
Osservatorio Astronomico di Trieste
M. Moyano
Universidad Catolica del Norte
C.A. Murray
University of Cambridge
Valerio Nascimbeni
Istituto nazionale di astrofisica (INAF)
N.J. Nunes
Universidade de Lisboa
G. Olofsson
Stockholms universitet
H. P. Osborn
Universität Bern
M. Oshagh
Instituto de Astrofísica de Canarias
R. Ottensamer
Universität Wien
I. Pagano
Istituto nazionale di astrofisica (INAF)
E. Palle
Instituto de Astrofísica de Canarias
P.P. Pedersen
University of Cambridge
Francesco Pepe
Université de Genève
Carina Persson
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
G. Peter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Giampaolo P. Piotto
Istituto nazionale di astrofisica (INAF)
G. Polenta
Agenzia Spaziale Italiana
Don L. Pollacco
The University of Warwick
E. Poretti
Istituto nazionale di astrofisica (INAF)
Francisco J. Pozuelos
Universite de Liège
D. Queloz
Université de Genève
Roberto Ragazzoni
Istituto nazionale di astrofisica (INAF)
N. Rando
European Space Research and Technology Centre (ESA ESTEC)
F. Ratti
European Space Research and Technology Centre (ESA ESTEC)
H. Rauer
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
L. Raynard
University Of Leicester
R. Rebolo
Instituto de Astrofísica de Canarias
C. Reimers
Universität Wien
I. Ribas
Institut de Ciències de l'Espai (ICE) - CSIC
N. C. Santos
Universidade do Porto
Gaetano Scandariato
Istituto nazionale di astrofisica (INAF)
J. Schneider
Observatoire de Paris
D. Sebastian
University of Birmingham
M. Sestovic
Universität Bern
A.E. Simon
Universität Bern
Alexis M. S. Smith
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
S.G. Sousa
Universidade do Porto
A. Sozzetti
Istituto nazionale di astrofisica (INAF)
Manfred B. Steller
Institut fur Weltraumforschung
A. Sua´rez Mascareno&tild;
Instituto de Astrofísica de Canarias
G.M. Szabó
Eötvös Loránd University (ELTE)
D. Segransan
Université de Genève
Nicolas Thomas
Universität Bern
S. Thompson
University of Cambridge
R.H. Tilbrook
University Of Leicester
Amaury Triaud
University of Birmingham
O. Turner
Université de Genève
S. Udry
Université de Genève
V. Van Grootel
Universite de Liège
H. Venus
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
F. Verrecchia
Agenzia Spaziale Italiana
José I. Vines
Camino El Observatorio 1515
N. A. Walton
University of Cambridge
R.G. West
The University of Warwick
P.J. Wheatley
The University of Warwick
D. Wolter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
M. Zapatero-Osorio
Centro de Astrobiologia (CAB)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 649 A26Exoplaneter 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.
Exoplaneter från rymden - CHEOPS och PLATO, ESA's nästa två missioner
Rymdstyrelsen (174/18), 2017-01-01 -- 2022-12-31.
Ämneskategorier
Astronomi, astrofysik och kosmologi
Annan fysik
Inbäddad systemteknik
DOI
10.1051/0004-6361/202039767