Unveiling the internal structure and formation history of the three planets transiting HIP 29442 (TOI-469) with CHEOPS
Artikel i vetenskaplig tidskrift, 2024
Multiplanetary systems spanning the radius valley are ideal testing grounds for exploring the different proposed explanations for the observed bimodality in the radius distribution of close-in exoplanets. One such system is HIP 29442 (TOI-469), an evolved K0V star hosting two super-Earths and one sub-Neptune. We observed HIP 29442 with CHEOPS for a total of 9.6 days, which we modelled jointly with two sectors of TESS data to derive planetary radii of 3.410 ± 0.046, 1.551 ± 0.045, and 1.538 ± 0.049 R? for planets b, c, and d, which orbit HIP 29442 with periods of 13.6, 3.5, and 6.4 days, respectively. For planet d this value deviates by more than 3s from the median value reported in the discovery paper, leading us to conclude that caution is required when using TESS photometry to determine the radii of small planets with low per-transit signal-to-noise ratios and large gaps between observations. Given the high precision of these new radii, combining them with published RVs from ESPRESSO and HIRES provides us with ideal conditions to investigate the internal structure and formation pathways of the planets in the system. We introduced the publicly available code plaNETic, a fast and robust neural network-based Bayesian internal structure modelling framework. We then applied hydrodynamic models to explore the upper atmospheric properties of these inferred structures. Finally, we identified planetary system analogues in a synthetic population generated with the Bern model for planet formation and evolution. Based on this analysis, we find that the planets likely formed on opposing sides of the water iceline from a protoplanetary disk with an intermediate solid mass. We finally report that the observed parameters of the HIP 29442 system are compatible with a scenario where the second peak in the bimodal radius distribution corresponds to sub-Neptunes with a pure H/He envelope and with a scenario with water-rich sub-Neptunes.
planets and satellites: interiors
planets and satellites: formation
planets and satellites: individual: HIP 29442
techniques: photometric
planetary systems
Författare
J. A. Egger
Universität Bern
H. P. Osborn
Universität Bern
Massachusetts Institute of Technology (MIT)
D. Kubyshkina
Institut fur Weltraumforschung
C. Mordasini
Universität Bern
Y. Alibert
Universität Bern
Maximilian N. Günther
European Space Research and Technology Centre (ESA ESTEC)
M. Lendl
Université de Genève
A. Brandeker
Stockholms universitet
A. Heitzmann
Université de Genève
A. Leleu
Université de Genève
Universität Bern
Mario Damasso
Istituto nazionale di astrofisica (INAF)
A. Bonfanti
Institut fur Weltraumforschung
T.G. Wilson
The University of Warwick
S.G. Sousa
Universidade do Porto
J. Haldemann
Universität Bern
L. Delrez
Universite de Liège
KU Leuven
M.J. Hooton
University of Cambridge
Tiziano Zingales
Istituto nazionale di astrofisica (INAF)
Università di Padova
R. Luque
University of Chicago
R. Alonso
Universidad de la Laguna
Instituto de Astrofísica de Canarias
J. Asquier
European Space Research and Technology Centre (ESA ESTEC)
T. Bárczy
Admatis
D. Barrado Navascues
European Space Astronomy Centre (ESAC)
S.C.C. Barros
Universidade do Porto
W. Baumjohann
Institut fur Weltraumforschung
W. Benz
Universität Bern
N. Billot
Université de Genève
L. Borsato
Istituto nazionale di astrofisica (INAF)
C. Broeg
Universität Bern
M. Buder
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Castro-González
European Space Astronomy Centre (ESAC)
A. Collier Cameron
University of St Andrews
A. Correia
Centre for Physics of the University of Coimbra
D. Cortes
Airbus Group
Szilard Csizmadia
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
P. E. Cubillos
Istituto nazionale di astrofisica (INAF)
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)
D. Ehrenreich
Université de Genève
Anders Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Fortier
Universität Bern
L. Fossati
Institut fur Weltraumforschung
Malcolm Fridlund
Universiteit Leiden
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
D. Gandolfi
Universita degli Studi di Torino
K. Gazeas
University of Athens
Michaël Gillon
Universite de Liège
M. Gudel
Universität Wien
Ch. Helling
Technische Universität Graz
Institut fur Weltraumforschung
K. Isaak
European Space Research and Technology Centre (ESA ESTEC)
L. L. Kiss
Eötvös Loránd University (ELTE)
Magyar Tudomanyos Akademia
Judith Korth
Lunds universitet
K. W.F. Lam
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
J. Laskar
Observatoire de Paris
B. Lavie
Université de Genève
A. L. des Etangs
Institut d 'Astrophysique de Paris
C. Lovis
Université de Genève
A. Luntzer
Universität Wien
D. Magrin
Istituto nazionale di astrofisica (INAF)
P. Maxted
Keele University
Bruno Merín
European Space Astronomy Centre (ESAC)
M. Munari
Istituto nazionale di astrofisica (INAF)
Valerio Nascimbeni
Istituto nazionale di astrofisica (INAF)
G. Olofsson
Stockholms universitet
R. Ottensamer
Universität Wien
I. Pagano
Istituto nazionale di astrofisica (INAF)
Enric Palle
Universidad de la Laguna
Instituto de Astrofísica de Canarias
G. Peter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
D. Piazza
Universität Bern
Giampaolo P. Piotto
Istituto nazionale di astrofisica (INAF)
Università di Padova
Don L. Pollacco
The University of Warwick
D. Queloz
Eidgenössische Technische Hochschule Zürich (ETH)
University of Cambridge
Roberto Ragazzoni
Istituto nazionale di astrofisica (INAF)
Università di Padova
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
J. Rodrigues
Universidade do Porto
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)
M. Stalport
Universite de Liège
S. Sulis
Laboratoire d'Astrophysique de Marseille
G.M. Szabó
Eötvös Loránd University (ELTE)
S. Udry
Université de Genève
V. Van Grootel
Universite de Liège
J. Venturini
Université de Genève
E. Villaver
Instituto de Astrofísica de Canarias
Universidad de la Laguna
N. A. Walton
University of Cambridge
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 688 A223Exoplaneter 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
DOI
10.1051/0004-6361/202450472