An ultra-short-period super-Earth and a sub-Neptune orbiting the K dwarf TOI-4311
Artikel i vetenskaplig tidskrift, 2026
We report the discovery and characterization of the multiplanetary system around TOI-4311, a K dwarf kinematically between the Galactic thick disc and Hercules stream. TOI-4311 hosts an ultra-short-period super-Earth (P(Formula presented) 0.99 d, (Formula presented) R(Formula presented) ) and a longer period sub-Neptune (P(Formula presented) 15 d, (Formula presented) R(Formula presented) ) that was first detected in the Transiting Exoplanet Survey Satellite photometry. Using follow-up observations with CHaracterising ExOPlanet Satellite and High Accuracy Radial Velocity Planet Searcher (HARPS), we refine the planetary radius of both planets, derive the mass of planet b ((Formula presented) M(Formula presented) ), and confirm the planetary nature of planet c. Intriguingly, a third periodic signal is clearly detected in our HARPS Radial Velocities (RVs) that we cannot link to stellar activity. This signal could be attributed to a third planet (P(Formula presented) 38 d, Msin(i) = (Formula presented) M(Formula presented) ) in the system; however, with the current photometric data set we do not find a transit. Our dynamical analysis highlights that this potential outer planet would remain stable. Using the precise radius and mass for TOI-4311 b, we model its interior structure and find that it is very dense given the host star’s galactic kinematics and chemistry. Hence, this system could challenge current formation theories and provide insights into planet formation across the galaxy.
techniques: radial velocities
planets and satellites: detection
stars: individual: TOI-4311
planets and satellites: individual: TOI-4311 b & c
techniques: photometric
planets and satellites: interiors
Författare
Yoshi Eschen
The University of Warwick
T.G. Wilson
The University of Warwick
A. Collier Cameron
University of St Andrews
A. J. Mustill
Lunds universitet
J. A. Egger
Europeiska rymdorganisationen (ESA)
S. Ulmer-Moll
Universiteit Leiden
Universite de Liège
D. Gandolfi
Universita degli Studi di Torino
A. M.S. Smith
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
O. Demangeon
Universidade do Porto
S.G. Sousa
Universidade do Porto
A. Bonfanti
Institut fur Weltraumforschung
A. Correia
Universidade de Coimbra
V. Adibekyan
Universidade do Porto
G. Lacedelli
Instituto de Astrofísica de Canarias
Universidad de la Laguna
A. Brandeker
Stockholms universitet
C. Pezzotti
Universite de Liège
B. Akinsanmi
Université de Genève
Y. Alibert
Universität Bern
R. Alonso
Universidad de la Laguna
Instituto de Astrofísica de Canarias
T. Bárczy
Admatis
D. Barrado
Europeiska rymdorganisationen (ESA)
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
A. Castro-González
Université de Genève
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
B.O. Demory
Universität Bern
A. Derekas
Eötvös Loránd University (ELTE)
G. Di Persio
Istituto nazionale di astrofisica (INAF)
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
K. Gazeas
University of Athens
Michaël Gillon
Universite de Liège
M. Gudel
Universität Wien
Maximilian N. Günther
Europeiska rymdorganisationen (ESA)
A. Heitzmann
Université de Genève
Ch. Helling
Technische Universität Graz
Institut fur Weltraumforschung
K. Isaak
Europeiska rymdorganisationen (ESA)
Jon M. Jenkins
National Aeronautics and Space Administration (NASA)
Tatiana Keller
Universität Bern
L. L. Kiss
Eötvös Loránd University (ELTE)
Magyar Tudomanyos Akademia
D. Kitzmann
Universität Bern
Judith Korth
Université de Genève
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
Université de Genève
Universität Bern
M. Lendl
Université de Genève
D. Magrin
Istituto nazionale di astrofisica (INAF)
P. Maxted
Keele University
Bruno Merín
Europeiska rymdorganisationen (ESA)
C. Mordasini
Universität Bern
Valerio Nascimbeni
Istituto nazionale di astrofisica (INAF)
G. Olofsson
Stockholms universitet
H. P. Osborn
Eidgenössische Technische Hochschule Zürich (ETH)
Universität Bern
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)
G. Petitpas
Massachusetts Institute of Technology (MIT)
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
Istituto nazionale di astrofisica (INAF)
Università di Padova
N. Rando
Europeiska rymdorganisationen (ESA)
H. Rauer
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Freie Universität Berlin
I. Ribas
Consejo Superior de Investigaciones Científicas (CSIC)
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
N. C. Santos
Universidade do Porto
Gaetano Scandariato
Istituto nazionale di astrofisica (INAF)
D. Segransan
Université de Genève
Avi Shporer
Massachusetts Institute of Technology (MIT)
André M. Silva
Universidade do Porto
A.E. Simon
Universität Bern
R. Southworth
Europeiska rymdorganisationen (ESA)
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
S. Wolf
Universität Bern
C. Ziegler
Stephen F. Austin State University
Tiziano Zingales
Istituto nazionale di astrofisica (INAF)
Università di Padova
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 549 3 stag952Ämneskategorier (SSIF 2025)
Astronomi, astrofysik och kosmologi
DOI
10.1093/mnras/stag952