TOI-4438 b: a transiting mini-Neptune amenable to atmospheric characterization
Artikel i vetenskaplig tidskrift, 2024
We report the confirmation and mass determination of a mini-Neptune transiting the M3.5 V star TOI-4438 (G 182-34) every 7.44 days. A transit signal was detected with NASA's TESS space mission in the sectors 40, 52, and 53. In order to validate the planet TOI-4438 b and to determine the system properties, we combined TESS data with high-precision radial velocity measurements from the CARMENES spectrograph, spanning almost one year, and ground-based transit photometry. We found that TOI-4438 b has a radius of Rb = 2.52 ± 0.13 R⊕ (5% precision), which together with a mass of Mb = 5.4 ± 1.1 M⊕ (20% precision), results in a bulk density of ρb = 1.85-0.44+0.51 g cm-3 (~28% precision), aligning the discovery with a volatile-rich planet. Our interior structure retrieval with a pure water envelope yields aminimum water mass fraction of 46% (1σ). TOI-4438 b is a volatile-rich mini-Neptune with likely H/He mixed with molecules, such as water, CO2, and CH4. The primary star has a J-band magnitude of 9.7, and the planet has a high transmission spectroscopy metric (TSM) of 136 ± 13. Taking into account the relatively warm equilibrium temperature of Teq = 435 ± 15 K, and the low activity level of its host star, TOI-4438 b is one of the most promising mini-Neptunes around an M dwarf for transmission spectroscopy studies.
Planets and satellites: composition
Techniques: photometric
Techniques: radial velocities
Planets and satellites: detection
Författare
E. Goffo
Universita degli Studi di Torino
Thüringer Landessternwarte Tautenburg
Priyanka Chaturvedi
Thüringer Landessternwarte Tautenburg
F. Murgas
Instituto de Astrofísica de Canarias
Universidad de la Laguna
Giuseppe Morello
Instituto de Astrofisica de Andalucía (IAA)
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Instituto de Astrofísica de Canarias
J. Orell-Miquel
Universidad de la Laguna
Instituto de Astrofísica de Canarias
L. Acuña
Max-Planck-Gesellschaft
L. Peña-Moñino
Instituto de Astrofisica de Andalucía (IAA)
Enric Palle
Instituto de Astrofísica de Canarias
Universidad de la Laguna
A. Hatzes
Thüringer Landessternwarte Tautenburg
S. Geraldía-González
Universidad de la Laguna
Instituto de Astrofísica de Canarias
Francisco J. Pozuelos
Instituto de Astrofisica de Andalucía (IAA)
A. F. Lanza
Istituto nazionale di astrofisica (INAF)
D. Gandolfi
Universita degli Studi di Torino
J. A. Caballero
Centro de Astrobiologia (CAB)
M. Schlecker
University of Arizona
M.A. Pérez-Torres
European University Cyprus
Instituto de Astrofisica de Andalucía (IAA)
Universidad de Zaragoza
N. Lodieu
Universidad de la Laguna
Instituto de Astrofísica de Canarias
A. Schweitzer
Universität Hamburg
Coel Hellier
Keele University
S. V. Jeffers
Max-Planck-Gesellschaft
C. Duque-Arribas
IPARCOS-UCM (Instituto de Física de Partículas y del Cosmos)
C. Cifuentes
Centro de Astrobiologia (CAB)
V. J. S. Bejar
Instituto de Astrofísica de Canarias
Universidad de la Laguna
M. Daspute
Ariel University
F. Dubois
Vereniging Voor Sterrenkunde (VVS)
IRIS
S. Dufoer
Vereniging Voor Sterrenkunde (VVS)
E. Esparza-Borges
Universidad de la Laguna
Instituto de Astrofísica de Canarias
A. Fukui
University of Tokyo
Instituto de Astrofísica de Canarias
Y. Hayashi
University of Tokyo
Enrique Herrero
Institut d'Estudis Espacials de Catalunya (IEEC)
M. Mori
University of Tokyo
Norio Narita
University of Tokyo
Instituto de Astrofísica de Canarias
National Institutes of Natural Sciences
H. Parviainen
Instituto de Astrofísica de Canarias
Universidad de la Laguna
L. Tal-Or
Ariel University
S. Vanaverbeke
Vereniging Voor Sterrenkunde (VVS)
IRIS
KU Leuven
I. Hermelo
Calar Alto Astronomical Observatory
P. J. Amado
Instituto de Astrofisica de Andalucía (IAA)
S. Dreizler
Georg-August-Universität Göttingen
T. Henning
Max-Planck-Gesellschaft
J. Lillo-Box
Centro de Astrobiologia (CAB)
R. Luque
University of Chicago
Instituto de Astrofisica de Andalucía (IAA)
M. Mallorquín
Instituto de Astrofísica de Canarias
Universidad de la Laguna
E. Nagel
Georg-August-Universität Göttingen
A. Quirrenbach
Landessternwarte Heidelberg-Königstuhl
S. Reffert
Landessternwarte Heidelberg-Königstuhl
A. Reiners
Georg-August-Universität Göttingen
I. Ribas
Institut de Ciències de l'Espai (ICE) - CSIC
Institut d'Estudis Espacials de Catalunya (IEEC)
P. Schöfer
Instituto de Astrofisica de Andalucía (IAA)
H. M. Tabernero
Centro de Astrobiologia (CAB)
IPARCOS-UCM (Instituto de Física de Partículas y del Cosmos)
M. Zechmeister
Georg-August-Universität Göttingen
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 685 A147Ämneskategorier
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/202349133