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.
Techniques: photometric
Planets and satellites: composition
Techniques: radial velocities
Planets and satellites: detection
Författare
E. Goffo
Thüringer Landessternwarte Tautenburg
Universita degli Studi di Torino
Priyanka Chaturvedi
Thüringer Landessternwarte Tautenburg
F. Murgas
Universidad de la Laguna
Instituto de Astrofísica de Canarias
Giuseppe Morello
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Instituto de Astrofísica de Canarias
Consejo Superior de Investigaciones Científicas (CSIC)
J. Orell-Miquel
Instituto de Astrofísica de Canarias
Universidad de la Laguna
L. Acuña
Max-Planck-Gesellschaft
L. Peña-Moñino
Consejo Superior de Investigaciones Científicas (CSIC)
Enric Palle
Instituto de Astrofísica de Canarias
Universidad de la Laguna
A. Hatzes
Thüringer Landessternwarte Tautenburg
S. Geraldía-González
Instituto de Astrofísica de Canarias
Universidad de la Laguna
Francisco J. Pozuelos
Consejo Superior de Investigaciones Científicas (CSIC)
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
Universidad de Zaragoza
Consejo Superior de Investigaciones Científicas (CSIC)
European University Cyprus
N. Lodieu
Instituto de Astrofísica de Canarias
Universidad de la Laguna
A. Schweitzer
Universität Hamburg
Coel Hellier
Keele University
S. V. Jeffers
Max-Planck-Gesellschaft
C. Duque-Arribas
Universidad Complutense de Madrid
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
IRIS
Vereniging Voor Sterrenkunde (VVS)
S. Dufoer
Vereniging Voor Sterrenkunde (VVS)
E. Esparza-Borges
Universidad de la Laguna
Instituto de Astrofísica de Canarias
A. Fukui
Instituto de Astrofísica de Canarias
University of Tokyo
Y. Hayashi
University of Tokyo
Enrique Herrero
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
M. Mori
University of Tokyo
Norio Narita
National Institutes of Natural Sciences
University of Tokyo
Instituto de Astrofísica de Canarias
H. Parviainen
Instituto de Astrofísica de Canarias
Universidad de la Laguna
L. Tal-Or
Ariel University
S. Vanaverbeke
IRIS
KU Leuven
Vereniging Voor Sterrenkunde (VVS)
I. Hermelo
Calar Alto Astronomical Observatory
P. J. Amado
Consejo Superior de Investigaciones Científicas (CSIC)
S. Dreizler
Georg-August-Universität Göttingen
T. Henning
Max-Planck-Gesellschaft
J. Lillo-Box
Centro de Astrobiologia (CAB)
R. Luque
Consejo Superior de Investigaciones Científicas (CSIC)
University of Chicago
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
Consejo Superior de Investigaciones Científicas (CSIC)
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
P. Schöfer
Consejo Superior de Investigaciones Científicas (CSIC)
M. Zechmeister
Georg-August-Universität Göttingen
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 685 A147Ämneskategorier (SSIF 2011)
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/202349133