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

planetary systems

techniques: photometric

planets and satellites: individual: HIP 29442

planets and satellites: formation

Författare

J. A. Egger

Universität Bern

H. P. Osborn

Massachusetts Institute of Technology (MIT)

Universität Bern

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

Università di Padova

Istituto nazionale di astrofisica (INAF)

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

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

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

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

Ch. Helling

Institut fur Weltraumforschung

Technische Universität Graz

K. Isaak

European Space Research and Technology Centre (ESA ESTEC)

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

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

Università di Padova

Istituto nazionale di astrofisica (INAF)

Don L. Pollacco

The University of Warwick

D. Queloz

Eidgenössische Technische Hochschule Zürich (ETH)

University of Cambridge

Roberto Ragazzoni

Università di Padova

Istituto nazionale di astrofisica (INAF)

N. Rando

European Space Research and Technology Centre (ESA ESTEC)

H. Rauer

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

Freie Universität Berlin

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 A223

Exoplaneter från rymden - CHEOPS och PLATO, ESA's nästa två rymdteleskop (fas 2)

Rymdstyrelsen (177/19), 2020-01-01 -- 2022-12-31.

Rymdstyrelsen (65/19), 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 (SSIF 2011)

Astronomi, astrofysik och kosmologi

DOI

10.1051/0004-6361/202450472

Mer information

Senast uppdaterat

2025-02-03