The K2-24 planetary system revisited by CHEOPS
Artikel i vetenskaplig tidskrift, 2024
The planetary system K2-24 is composed of two transiting low-density Neptunians locked in an almost perfect 2:1 resonance and showing large transit time variations (TTVs), and it is an excellent laboratory to search for signatures of planetary migration. Previous studies performed with K2, Spitzer, and RV data tentatively claimed a significant non-zero eccentricity for one or both planets, possibly high enough to challenge the scenario of pure disk migration through resonant capture. With 13 new CHEOPS light curves (seven of planet b, six of planet c), we carried out a global photometric and dynamical re-analysis by including all the available literature data as well. We obtained the most accurate set of planetary parameters to date for the K2-24 system, including radii and masses at 1% and 5% precision (now essentially limited by the uncertainty on stellar parameters) and non-zero eccentricities eb = 0.0498-0.0018+0.0011, ec = 0.0282-0.0007+0.0003 detected at very high significance for both planets. Such relatively large values imply the need for an additional physical mechanism of eccentricity excitation during or after the migration stage. Also, while the accuracy of the previous TTV model had drifted by up to 0.5 days at the current time, we constrained the orbital solution firmly enough to predict the forthcoming transits for the next ~15 years, thus enabling efficient follow-up with top-level facilities such as JWST or ESPRESSO.
Techniques: photometric
Planets and satellites: dynamical evolution and stability
Planets and satellites: gaseous planets
Techniques: spectroscopic
Planets and satellites: detection
Författare
Valerio Nascimbeni
Istituto nazionale di astrofisica (INAF)
L. Borsato
Istituto nazionale di astrofisica (INAF)
P. Leonardi
Università di Padova
Universita degli Studi di Trento
Istituto nazionale di astrofisica (INAF)
S.G. Sousa
Universidade do Porto
T.G. Wilson
The University of Warwick
A. Fortier
Universität Bern
A. Heitzmann
Université de Genève
G. Mantovan
Università di Padova
Istituto nazionale di astrofisica (INAF)
R. Luque
University of Chicago
Tiziano Zingales
Istituto nazionale di astrofisica (INAF)
Università di Padova
Giampaolo P. Piotto
Istituto nazionale di astrofisica (INAF)
Università di Padova
Y. Alibert
Universität Bern
R. Alonso
Universidad de la Laguna
Instituto de Astrofísica de Canarias
T. Bárczy
Admatis
D. Barrado Navascues
European Space Astronomy Centre (ESAC)
S.C.C. Barros
Universidade do Porto
W. Baumjohann
Institut fur Weltraumforschung
T. Beck
Universität Bern
W. Benz
Universität Bern
N. Billot
Université de Genève
F. Biondi
Max-Planck-Gesellschaft
Istituto nazionale di astrofisica (INAF)
A. Brandeker
Stockholms universitet
C. Broeg
Universität Bern
M.-D. Busch
Universität Bern
A. Collier Cameron
University of St Andrews
A. Correia
Centre for Physics of the University of Coimbra
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
A. Deline
Université de Genève
L. Delrez
KU Leuven
Universite de Liège
O. Demangeon
Universidade do Porto
B.O. Demory
Universität Bern
A. Derekas
Eötvös Loránd University (ELTE)
Billy Edwards
Netherlands Institute for Space Research (SRON)
D. Ehrenreich
Université de Genève
Anders Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
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
Michaël Gillon
Universite de Liège
M. Gudel
Universität Wien
Maximilian N. Günther
European Space Research and Technology Centre (ESA ESTEC)
Ch. Helling
Technische Universität Graz
Institut fur Weltraumforschung
K. Isaak
European Space Research and Technology Centre (ESA ESTEC)
F. Kerschbaum
Universität Wien
L. L. Kiss
Magyar Tudomanyos Akademia
Eötvös Loránd University (ELTE)
Judith Korth
Lunds universitet
K. W.F. Lam
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
J. Laskar
Observatoire de Paris
A. L. des Etangs
Institut d 'Astrophysique de Paris
A. Leleu
Universität Bern
Université de Genève
M. Lendl
Université de Genève
D. Magrin
Istituto nazionale di astrofisica (INAF)
P. Maxted
Keele University
Bruno Merín
European Space Astronomy Centre (ESAC)
C. Mordasini
Universität Bern
G. Olofsson
Stockholms universitet
R. Ottensamer
Universität Wien
I. Pagano
Istituto nazionale di astrofisica (INAF)
Enric Palle
Instituto de Astrofísica de Canarias
Universidad de la Laguna
G. Peter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Don L. Pollacco
The University of Warwick
D. Queloz
University of Cambridge
Eidgenössische Technische Hochschule Zürich (ETH)
Roberto Ragazzoni
Università di Padova
Istituto nazionale di astrofisica (INAF)
N. Rando
European Space Research and Technology Centre (ESA ESTEC)
H. Rauer
Freie Universität Berlin
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
I. Ribas
Institut d'Estudis Espacials de Catalunya (IEEC)
Institut de Ciències de l'Espai (ICE) - CSIC
N. C. Santos
Universidade do Porto
Gaetano 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)
R. Southworth
European Space Operations Centre
M. Stalport
Universite de Liège
S. Sulis
Laboratoire d'Astrophysique de Marseille
G.M. Szabó
Eötvös Loránd University (ELTE)
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
E. Villaver
Universidad de la Laguna
Instituto de Astrofísica de Canarias
N. A. Walton
University of Cambridge
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 690 A349Ämneskategorier
Astronomi, astrofysik och kosmologi
Annan fysik
DOI
10.1051/0004-6361/202450852