TOI-1442 b and TOI-2445 b: Two potentially rocky ultra-short period planets around M dwarfs
Journal article, 2023
Context. Exoplanets with orbital periods of less than one day are known as ultra-short period (USP) planets. They are relatively rare products of planetary formation and evolution processes, but especially favourable for characterisation with current planet detection methods. At the time of writing, 125 USP planets have already been confirmed. Aims. Our aim is to validate the planetary nature of two new transiting planet candidates around M dwarfs announced by the NASA Transiting Exoplanet Survey Satellite (TESS), registered as TESS Objects of Interest (TOIs) TOI-1442.01 and TOI-2445.01. Methods. We used TESS data, ground-based photometric light curves, and Subaru/IRD spectrograph radial velocity (RV) measurements to validate both planetary candidates and to establish their physical properties. Results. TOI-1442 b is a validated exoplanet with an orbital period of P = 0.4090682 ± 0.0000004 day, a radius of Rp = 1.15 ± 0.06 R☉, and equilibrium temperature of Tp,eq = 1357+−4942 K. TOI-2445 b is also validated with an orbital period of P = 0.3711286 ± 0.0000004 day, a radius of Rp = 1.33 ± 0.09 R☉, and equilibrium temperature of Tp,eq = 1330+−6156 K. Their physical properties align with current empirical trends and formation theories of USP planets. Based on the RV measurements, we set 3σ upper mass limits of 8 M☉ and 20 M☉, thus confirming the non-stellar, sub-Jovian nature of both transiting objects. More RV measurements will be needed to constrain the planetary masses and mean densities, and the predicted presence of outer planetary companions. These targets extend the small sample of USP planets orbiting around M dwarfs up to 21 members. They are also among the 20 most suitable terrestrial planets for atmospheric characterisation via secondary eclipse with the James Webb Space Telescope, according to a widespread emission spectroscopy metric.
techniques: photometric
methods: observational
planets and satellites: individual: TOI-1442 b
techniques: spectroscopic
planets and satellites: individual: TOI-2445 b
planetary systems
Author
Giuseppe Morello
University of La Laguna
Instituto de Astrofísica de Canarias
Istituto nazionale di astrofisica (INAF)
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
H. Parviainen
University of La Laguna
Instituto de Astrofísica de Canarias
F. Murgas
University of La Laguna
Instituto de Astrofísica de Canarias
E. Palle
Instituto de Astrofísica de Canarias
University of La Laguna
M. Oshagh
Instituto de Astrofísica de Canarias
University of La Laguna
A. Fukui
University of Tokyo
Instituto de Astrofísica de Canarias
T. Hirano
National Astronomical Observatory of Japan
National Institutes of Natural Sciences
Hiroyuki Tako Ishikawa
National Astronomical Observatory of Japan
National Institutes of Natural Sciences
Mayuko Mori
University of Tokyo
Norio Narita
Instituto de Astrofísica de Canarias
University of Tokyo
National Institutes of Natural Sciences
K. A. Collins
Harvard-Smithsonian Center for Astrophysics
Khalid Barkaoui
Massachusetts Institute of Technology (MIT)
Instituto de Astrofísica de Canarias
University of Liège
Pablo Lewin
Maury Lewin Astronomical Observatory
C. Cadieux
Université de Montréal
Jerome P. De Leon
University of Tokyo
A. Soubkiou
University of Porto
Cadi Ayyad University
N. Abreu Garcia
Instituto de Astrofísica de Canarias
University of La Laguna
N. Crouzet
European Space Research and Technology Centre (ESA ESTEC)
E. Esparza-Borges
Instituto de Astrofísica de Canarias
University of La Laguna
G. E.Fernández Rodríguez
Instituto de Astrofísica de Canarias
D. Galán
Instituto de Astrofísica de Canarias
University of La Laguna
Yasunori Hori
National Astronomical Observatory of Japan
National Institutes of Natural Sciences
Masahiro Ikoma
National Institutes of Natural Sciences
K. Isogai
Kyoto University
University of Tokyo
T. Kagetani
University of Tokyo
Kiyoe Kawauchi
Instituto de Astrofísica de Canarias
University of La Laguna
University of Tokyo
Tadahiro Kimura
University of Tokyo
T. Kodama
University of Tokyo
Judith Korth
Lund University
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Takayuki Kotani
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
National Institutes of Natural Sciences
Vigneshwaran Krishnamurthy
National Astronomical Observatory of Japan
National Institutes of Natural Sciences
S. Kurita
University of Tokyo
A. Laza-Ramos
Instituto de Astrofísica de Canarias
J. Livingston
University of Tokyo
R. Luque
Institute of Astrophysics of Andalusia (IAA)
A. Madrigal-Aguado
Instituto de Astrofísica de Canarias
University of La Laguna
T. Nishiumi
National Institutes of Natural Sciences
The Graduate University for Advanced Studies (SOKENDAI)
University of Tokyo
J. Orell-Miquel
Instituto de Astrofísica de Canarias
University of La Laguna
M. Puig-Subirà
Instituto de Astrofísica de Canarias
University of La Laguna
M. Sánchez-Benavente
University of La Laguna
Instituto de Astrofísica de Canarias
M. Stangret
Instituto de Astrofísica de Canarias
Istituto nazionale di astrofisica (INAF)
University of La Laguna
Motohide Tamura
National Institutes of Natural Sciences
National Astronomical Observatory of Japan
University of Tokyo
Y. Terada
Academia Sinica
National Taiwan University
Noriharu Watanabe
University of Tokyo
Y. Zou
University of Tokyo
Z. Benkhaldoun
Cadi Ayyad University
K. I. Collins
George Mason University
René Doyon
Université de Montréal
L.J. Garcia
University of Liège
M. Ghachoui
Cadi Ayyad University
University of Liège
Michaël Gillon
University of Liège
Emmanuel Jehin
University of Liège
Francisco J. Pozuelos
University of Liège
Institute of Astrophysics of Andalusia (IAA)
R. P. Schwarz
Harvard-Smithsonian Center for Astrophysics
M. Timmermans
University of Liège
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 673 A32Subject Categories
Subatomic Physics
Astronomy, Astrophysics and Cosmology
DOI
10.1051/0004-6361/202243592