Photo-dynamical characterisation of the TOI-178 resonant chain: Exploring the robustness of transit-timing variations and radial velocity mass characterisations
Artikel i vetenskaplig tidskrift, 2024
Context. The TOI-178 system consists of a nearby, late-K-dwarf with six transiting planets in the super-Earth to mini-Neptune regime, with radii ranging from ∼1.1 to 2.9 R⊕ and orbital periods between 1.9 and 20.7 days. All the planets, but the innermost one, form a chain of Laplace resonances. The fine-tuning and fragility of such orbital configurations ensure that no significant scattering or collision event has taken place since the formation and migration of the planets in the protoplanetary disc, thereby providing important anchors for planet formation models. Aims. We aim to improve the characterisation of the architecture of this key system and, in particular, the masses and radii of its planets. In addition, since this system is one of the few resonant chains that can be characterised by both photometry and radial velocities, we propose to use it as a test bench for the robustness of the planetary mass determination with each technique. Methods. We performed a global analysis of all the available photometry from CHEOPS, TESS and NGTS, and radial velocity from ESPRESSO, using a photo-dynamical modelling of the light curve.We also tried different sets of priors on the masses and eccentricity, as well as different stellar activity models, to study their effects on the masses estimated by transit-timing variations (TTVs) and radial velocities (RVs). Results. We demonstrate how stellar activity prevents a robust mass estimation for the three outer planets using radial velocity data alone.We also show that our joint photo-dynamical and radial velocity analysis has resulted in a robust mass determination for planets c to g, with precision of ∼12% for the mass of planet c, and better than 10% for planets d to g. The new precisions on the radii range from 2 to 3%. The understanding of this synergy between photometric and radial velocity measurements will be valuable for the PLATO mission. We also show that TOI-178 is indeed currently locked in the resonant configuration, librating around an equilibrium of the chain.
Techniques: radial velocities
Techniques: photometric
Planets and satellites: gaseous planets
Methods: data analysis
Planets and satellites: detection
Författare
A. Leleu
Université de Genève
J. B. Delisle
Université de Genève
L. Delrez
Universite de Liège
E. Bryant
University College London (UCL)
A. Brandeker
Stockholms universitet
H. P. Osborn
Universität Bern
N.C. Hara
Université de Genève
T.G. Wilson
The University of Warwick
N. Billot
Université de Genève
M. Lendl
Université de Genève
D. Ehrenreich
Université de Genève
Hritam Chakraborty
Université de Genève
Maximilian N. Günther
Europeiska rymdorganisationen (ESA)
M.J. Hooton
University of Cambridge
Y. Alibert
Physics Institute
R. Alonso
Instituto de Astrofísica de Canarias
Douglas R. Alves
Universidad de Chile (UCH)
D. Anderson
Universidad Catolica del Norte
I. Apergis
The University of Warwick
D. J. Armstrong
The University of Warwick
T. Bárczy
Admatis
D. Barrado
Centro de Astrobiologia (CAB)
S.C.C. Barros
Universidade do Porto
M. P. Battley
Université de Genève
W. Baumjohann
Institut fur Weltraumforschung
D. Bayliss
The University of Warwick
T. Beck
Universität Bern
W. Benz
Universität Bern
L. Borsato
Istituto nazionale di astrofisica (INAF)
C. Broeg
Physics Institute
Matt Burleigh
University Of Leicester
Sarah Casewell
University Of Leicester
A. Collier Cameron
University of St Andrews
A. Correia
Universidade de Coimbra
Szilard Csizmadia
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
P. E. Cubillos
Institut fur Weltraumforschung
Melvyn B. Davies
Lunds universitet
M. Deleuil
Laboratoire d'Astrophysique de Marseille
A. Deline
Université de Genève
O. Demangeon
Universidade do Porto
B.O. Demory
Universität Bern
A. Derekas
Eötvös Loránd University (ELTE)
Billy Edwards
Netherlands Institute for Space Research (SRON)
Anders Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Fortier
Universität Bern
L. Fossati
Institut fur Weltraumforschung
Malcolm Fridlund
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Universiteit Leiden
D. Gandolfi
Universita degli Studi di Torino
K. Gazeas
University of Athens
E. Gillen
Queen Mary University of London
Michaël Gillon
Universite de Liège
M.R. Goad
University Of Leicester
M. Gudel
Universität Wien
F. Hawthorn
The University of Warwick
A. Heitzmann
Université de Genève
Ch. Helling
Institut fur Weltraumforschung
K. Isaak
Europeiska rymdorganisationen (ESA)
James S. Jenkins
Universidad Diego Portales
Jon M. Jenkins
National Aeronautics and Space Administration (NASA)
Alicia Kendall
University Of Leicester
L. L. Kiss
Magyar Tudomanyos Akademia
Judith Korth
Lunds universitet
K. W.F. Lam
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
J. Laskar
Observatoire de Paris
D. W. Latham
Harvard-Smithsonian Center for Astrophysics
A. L. des Etangs
Institut d 'Astrophysique de Paris
D. Magrin
Istituto nazionale di astrofisica (INAF)
P. Maxted
Keele University
J. McCormac
The University of Warwick
C. Mordasini
Universität Bern
M. Moyano
Universidad Catolica del Norte
Valerio Nascimbeni
Istituto nazionale di astrofisica (INAF)
G. Olofsson
Stockholms universitet
A. Osborn
McMaster University
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)
Don L. Pollacco
The University of Warwick
D. Queloz
University of Cambridge
Roberto Ragazzoni
Istituto nazionale di astrofisica (INAF)
N. Rando
Europeiska rymdorganisationen (ESA)
H. Rauer
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
I. Ribas
Consejo Superior de Investigaciones Científicas (CSIC)
George R. Ricker
Massachusetts Institute of Technology (MIT)
S. Saha
Universidad Diego Portales
N. C. Santos
Universidade do Porto
Gaetano Scandariato
Istituto nazionale di astrofisica (INAF)
S. Seager
Massachusetts Institute of Technology (MIT)
D. Segransan
Université de Genève
A.E. Simon
Universität Bern
A. M.S. Smith
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
S.G. Sousa
Universidade do Porto
M. Stalport
Universite de Liège
S. Sulis
Laboratoire d'Astrophysique de Marseille
Gy M. Szabó
Eötvös Loránd University (ELTE)
S. Udry
Université de Genève
S. Ulmer-Moll
Université de Genève
V. Van Grootel
Universite de Liège
Roland K. Vanderspek
Massachusetts Institute of Technology (MIT)
J. Venturini
Université de Genève
E. Villaver
Instituto de Astrofísica de Canarias
José I. Vines
Universidad Catolica del Norte
N. A. Walton
University of Cambridge
Richard G West
The University of Warwick
P. J. Wheatley
The University of Warwick
J. N. Winn
Princeton University
T. Zivave
The University of Warwick
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 688 A211Ämneskategorier (SSIF 2025)
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/202450212