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.

planets and satellites: individual: TOI-2445 b

methods: observational

planets and satellites: individual: TOI-1442 b

techniques: photometric

techniques: spectroscopic

planetary systems

Author

Giuseppe Morello

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

University of La Laguna

Istituto nazionale di astrofisica (INAF)

Instituto de Astrofísica de Canarias

H. Parviainen

University of La Laguna

Instituto de Astrofísica de Canarias

F. Murgas

Instituto de Astrofísica de Canarias

University of La Laguna

E. Palle

University of La Laguna

Instituto de Astrofísica de Canarias

M. Oshagh

University of La Laguna

Instituto de Astrofísica de Canarias

A. Fukui

Instituto de Astrofísica de Canarias

University of Tokyo

T. Hirano

National Institutes of Natural Sciences

National Astronomical Observatory of Japan

Hiroyuki Tako Ishikawa

National Institutes of Natural Sciences

National Astronomical Observatory of Japan

Mayuko Mori

University of Tokyo

Norio Narita

University of Tokyo

Instituto de Astrofísica de Canarias

National Institutes of Natural Sciences

K. A. Collins

Harvard-Smithsonian Center for Astrophysics

Khalid Barkaoui

Instituto de Astrofísica de Canarias

Massachusetts Institute of Technology (MIT)

University of Liège

Pablo Lewin

Maury Lewin Astronomical Observatory

C. Cadieux

Université de Montréal

Jerome P. De Leon

University of Tokyo

A. Soubkiou

Cadi Ayyad University

University of Porto

N. Abreu Garcia

University of La Laguna

Instituto de Astrofísica de Canarias

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

University of La Laguna

Instituto de Astrofísica de Canarias

Yasunori Hori

National Institutes of Natural Sciences

National Astronomical Observatory of Japan

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 Tokyo

University of La Laguna

Tadahiro Kimura

University of Tokyo

T. Kodama

University of Tokyo

Judith Korth

Lund University

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Takayuki Kotani

National Institutes of Natural Sciences

The Graduate University for Advanced Studies (SOKENDAI)

National Astronomical Observatory of Japan

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

Spanish National Research Council (CSIC)

A. Madrigal-Aguado

University of La Laguna

Instituto de Astrofísica de Canarias

T. Nishiumi

National Institutes of Natural Sciences

University of Tokyo

The Graduate University for Advanced Studies (SOKENDAI)

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

Instituto de Astrofísica de Canarias

University of La Laguna

M. Stangret

Instituto de Astrofísica de Canarias

Istituto nazionale di astrofisica (INAF)

University of La Laguna

Motohide Tamura

University of Tokyo

National Astronomical Observatory of Japan

National Institutes of Natural Sciences

Y. Terada

National Taiwan University

Academia Sinica

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

Spanish National Research Council (CSIC)

R. P. Schwarz

Harvard-Smithsonian Center for Astrophysics

M. Timmermans

University of Liège

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 673 A32

Subject Categories (SSIF 2011)

Subatomic Physics

Astronomy, Astrophysics and Cosmology

DOI

10.1051/0004-6361/202243592

More information

Latest update

3/9/2025 1