Detection of an Earth-sized exoplanet orbiting the nearby ultracool dwarf star SPECULOOS-3
Creators: name: Gillon, Michaël
name: Pedersen, Peter P.
name: Rackham, Benjamin V.
name: Dransfield, Georgina
name: Ducrot, Elsa
name: Barkaoui, Khalid
name: Burdanov, Artem Y.
name: Schroffenegger, Urs
name: Chew, Yilen Gómez Maqueo
name: Lederer, Susan M.
name: Alonso, Roi
name: Burgasser, Adam J.
name: Howell, Steve B.
name: Narita, Norio
name: de Wit, Julien
name: Demory, Brice-Olivier
name: Queloz, Didier
name: Triaud, Amaury H. M. J.
name: Delrez, Laetitia
name: Jehin, Emmanuël
name: Hooton, Matthew J.
name: Garcia, Lionel J.
name: Muñoz, Clàudia Jano
name: Murray, Catriona A.
name: Pozuelos, Francisco J.
name: Sebastian, Daniel
name: Timmermans, Mathilde
name: Thompson, Samantha J.
name: 1, Sebastián Zúñiga-Fernández
name: Aceituno, Jesús
name: Aganze, Christian
name: Amado, Pedro J.
name: Baycroft, Thomas
name: Benkhaldoun, Zouhair
name: Berardo, David
name: Bolmont, Emeline
name: Clark, Catherine A.
name: Davis, Yasmin T.
name: Davoudi, Fatemeh
name: de Beurs, Zoë L.
name: de Leon, Jerome P.
name: Ikoma, Masahiro
name: Ikuta, Kai
name: Isogai, Keisuke
name: Fukuda, Izuru
name: Fukui, Akihiko
name: Gerasimov, Roman
name: Ghachoui, Mourad
name: Günther, Maximilian N.
name: Hasler, Samantha
name: Hayashi, Yuya
name: Heng, Kevin
name: Hu, Renyu
name: Kagetani, Taiki
name: Kawai, Yugo
name: Kawauchi, Kiyoe
name: Kitzmann, Daniel
name: Koll, Daniel D. B.
name: Lendl, Monika
name: Livingston, John H.
name: Lyu, Xintong
name: Valdés, Erik A. Meier
name: Mori, Mayuko
name: McCormac, James J.
name: Murgas, Felipe
name: Niraula, Prajwal
name: Pallé, Enric
name: Plauchu-Frayn, Ilse
name: Rebolo, Rafael
name: Sabin, Laurence
name: Schackey, Yannick
name: Schanche, Nicole
name: Selsis, Franck
name: Sota, Alfredo
name: Stalport, Manu
name: Standing, Matthew R.
name: Stassun, Keivan G.
name: Tamura, Motohide
name: Theissen, Christopher A.
name: Turbet, Martin
name: Van Grootel, Valérie
name: Varas, Roberto
name: Watanabe, Noriharu
name: Lang, Francis Zong
Publisher: name: arXiv
Year: 2024
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Located at the bottom of the main sequence, ultracool dwarf stars are widespread in the solar neighbourhood. Nevertheless, their extremely low luminosity has left their planetary population largely unexplored, and only one of them, TRAPPIST-1, has so far been found to host a transiting planetary system. In this context, we present the SPECULOOS project's detection of an Earth-sized planet in a 17 h orbit around an ultracool dwarf of M6.5 spectral type located 16.8 pc away. The planet's high irradiation (16 times that of Earth) combined with the infrared luminosity and Jupiter-like size of its host star make it one of the most promising rocky exoplanet targets for detailed emission spectroscopy characterization with JWST. Indeed, our sensitivity study shows that just ten secondary eclipse observations with the Mid-InfraRed Instrument/Low-Resolution Spectrometer on board JWST should provide strong constraints on its atmospheric composition and/or surface mineralogy.