_version_ 1866910049393180672
author Lang, F. Zong
Demory, B. O.
Chew, Y. Gomez Maqueo
Schmid, Y.
Timmermans, M.
Pozuelos, F. J.
Gillon, M.
Burdanov, Artem Y.
Rackham, Benjamin V.
Queloz, Didier
Stassun, Keivan G.
Barkaoui, Khalid
Triaud, Amaury
de Wit, Julien
Zuniga-Fernandez, S.
Burgasser, A. J.
Ducrot, Elsa
Scott, Madison G.
Sebastian, D.
Soubkiou, A.
Lendl, M.
Plauchu-Frayn, I.
Schroffenegger, U.
V., Erik Meier
Pedersen, P.
Khandelwal, A.
Gerasimov, Roman
Aganze, C.
Hsu, Chih-Chun
Jenkins, J. M.
Iyer, Aishwarya R.
Watkins, C.
Theissen, C. A.
Collins, K. A.
Osborn, H. P.
Shporer, A.
Munoz, Claudia Jano
Suganuma, Toshi
Narita, Norio
Fukui, Akihiko
Murgas, F.
de Leon, J.
Palle, Enric
Davis, Yasmin
Kitzmann, D.
Marcano, M. Pichardo
Hooton, M. J.
author_facet Lang, F. Zong
Demory, B. O.
Chew, Y. Gomez Maqueo
Schmid, Y.
Timmermans, M.
Pozuelos, F. J.
Gillon, M.
Burdanov, Artem Y.
Rackham, Benjamin V.
Queloz, Didier
Stassun, Keivan G.
Barkaoui, Khalid
Triaud, Amaury
de Wit, Julien
Zuniga-Fernandez, S.
Burgasser, A. J.
Ducrot, Elsa
Scott, Madison G.
Sebastian, D.
Soubkiou, A.
Lendl, M.
Plauchu-Frayn, I.
Schroffenegger, U.
V., Erik Meier
Pedersen, P.
Khandelwal, A.
Gerasimov, Roman
Aganze, C.
Hsu, Chih-Chun
Jenkins, J. M.
Iyer, Aishwarya R.
Watkins, C.
Theissen, C. A.
Collins, K. A.
Osborn, H. P.
Shporer, A.
Munoz, Claudia Jano
Suganuma, Toshi
Narita, Norio
Fukui, Akihiko
Murgas, F.
de Leon, J.
Palle, Enric
Davis, Yasmin
Kitzmann, D.
Marcano, M. Pichardo
Hooton, M. J.
contents Rocky exoplanets are particularly abundant around M-type stars. Their small radii and low luminosities provide favourable conditions for detecting transiting terrestrial planets and probing their atmospheric properties. We report the discovery and statistical validation of TOI-4616 b, an Earth-sized planet transiting a nearby mid-M dwarf observed by the Transiting Exoplanet Survey Satellite (TESS). We confirm the planetary nature of the signal and determine the system parameters by combining TESS photometry with ground-based multi-band transit observations, high-resolution imaging, and optical and near-infrared spectroscopy. The host star lies at a distance of 28.10 +(-) 0.07 pc and has a radius of 0.1889 +(-)0.0096 solar radii, a mass of 0.1881 +(-) 0.0094 solar masses, and an effective temperature of 3150 +(-) 75 K. TOI-4616 b has a radius of 1.22 Earth radii and an orbital period of 1.55 days. The planet receives an incident flux of approximately 40 times that of Earth, corresponding to an equilibrium temperature of about 525 K. This places TOI-4616 b in a regime intermediate between Earth-sized planets orbiting early M dwarfs and those around ultra-cool hosts. Statistical validation with the TRICERATOPS framework, supported by high-resolution imaging and chromatic transit constraints, yields a false-positive probability of 0.0135, below the recommended validation threshold of 0.015, confirming TOI-4616 b as a validated planet. Owing to its proximity to Earth, well-constrained stellar properties, and extensive multi-band follow-up, TOI-4616 b constitutes a valuable benchmark system for comparative studies of terrestrial planets around mid-M dwarfs and for future atmospheric investigations.
format Preprint
id arxiv_https___arxiv_org_abs_2603_10905
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle TOI-4616 b: a benchmark Earth-sized planet transiting a nearby M4 dwarf
Lang, F. Zong
Demory, B. O.
Chew, Y. Gomez Maqueo
Schmid, Y.
Timmermans, M.
Pozuelos, F. J.
Gillon, M.
Burdanov, Artem Y.
Rackham, Benjamin V.
Queloz, Didier
Stassun, Keivan G.
Barkaoui, Khalid
Triaud, Amaury
de Wit, Julien
Zuniga-Fernandez, S.
Burgasser, A. J.
Ducrot, Elsa
Scott, Madison G.
Sebastian, D.
Soubkiou, A.
Lendl, M.
Plauchu-Frayn, I.
Schroffenegger, U.
V., Erik Meier
Pedersen, P.
Khandelwal, A.
Gerasimov, Roman
Aganze, C.
Hsu, Chih-Chun
Jenkins, J. M.
Iyer, Aishwarya R.
Watkins, C.
Theissen, C. A.
Collins, K. A.
Osborn, H. P.
Shporer, A.
Munoz, Claudia Jano
Suganuma, Toshi
Narita, Norio
Fukui, Akihiko
Murgas, F.
de Leon, J.
Palle, Enric
Davis, Yasmin
Kitzmann, D.
Marcano, M. Pichardo
Hooton, M. J.
Earth and Planetary Astrophysics
Rocky exoplanets are particularly abundant around M-type stars. Their small radii and low luminosities provide favourable conditions for detecting transiting terrestrial planets and probing their atmospheric properties. We report the discovery and statistical validation of TOI-4616 b, an Earth-sized planet transiting a nearby mid-M dwarf observed by the Transiting Exoplanet Survey Satellite (TESS). We confirm the planetary nature of the signal and determine the system parameters by combining TESS photometry with ground-based multi-band transit observations, high-resolution imaging, and optical and near-infrared spectroscopy. The host star lies at a distance of 28.10 +(-) 0.07 pc and has a radius of 0.1889 +(-)0.0096 solar radii, a mass of 0.1881 +(-) 0.0094 solar masses, and an effective temperature of 3150 +(-) 75 K. TOI-4616 b has a radius of 1.22 Earth radii and an orbital period of 1.55 days. The planet receives an incident flux of approximately 40 times that of Earth, corresponding to an equilibrium temperature of about 525 K. This places TOI-4616 b in a regime intermediate between Earth-sized planets orbiting early M dwarfs and those around ultra-cool hosts. Statistical validation with the TRICERATOPS framework, supported by high-resolution imaging and chromatic transit constraints, yields a false-positive probability of 0.0135, below the recommended validation threshold of 0.015, confirming TOI-4616 b as a validated planet. Owing to its proximity to Earth, well-constrained stellar properties, and extensive multi-band follow-up, TOI-4616 b constitutes a valuable benchmark system for comparative studies of terrestrial planets around mid-M dwarfs and for future atmospheric investigations.
title TOI-4616 b: a benchmark Earth-sized planet transiting a nearby M4 dwarf
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2603.10905