The Discovery and Follow-up of Four Transiting Short-period Sub-Neptunes Orbiting M dwarfs

• Published in: arXiv.org 2024-05
• Main Authors: Hori, Y, Fukui, A, Hirano, T, Narita, N, de Leon, J P, Ishikawa, H T, Hartman, J D, Morello, G, N Abreu García, L Álvarez Hernández, Béjar, V J S, Calatayud-Borras, Y, Carleo, I, Enoc, G, Esparza-Borges, E, Fukuda, I, Galán, D, Geraldía-González, S, Hayashi, Y, Ikoma, M, Ikuta, K, Isogai, K, Kagetani, T, Kawai, Y, Kawauchi, K, Kimura, T, Kodama, T, Korth, J, Kusakabe, N, Laza-Ramos, A, Livingston, J H, Luque, R, Miyakawa, K, Mori, M, S Muñoz Torres, Murgas, F, Orell-Miquel, J, Palle, E, Parviainen, H, Peláez-Torres, A, Puig-Subirá, M, Sánchez-Benavente, M, Sosa-Guillén, P, Stangret, M, Terada, Y, Watanabe, N, Bakos, G Á, Barkaoui, K, Beichman, C, Benkhaldoun, Z, Boyle, A W, Ciardi, D R, Clark, C A, Collins, K A, Collins, K I, Conti, D M, Crossfield, I J M, Everett, M E, Furlan, E, Ghachoui, M, Gillon, M, Gonzales, E J, Higuera, J, Horne, K, Howell, S B, Jehin, E, Lester, K V, Lund, M B, Matson, R, Matthews, E C, Pozuelos, F J, Safonov, B S, Schlieder, J E, Sefako, R, Srdoc, G, Strakhov, I A, Waalkes, W C, Ziegler, C, Charbonneau, D, Essack, Z, Timmermans, M, Guerrero, N M, Harakawa, H, Hedges, C, Jenkins, J M, Konishi, M, Kudo, T, Kurokawa, T, Kuzuhara, M, Nishikawa, J, Omiya, M, Ricker, G R, Seager, S, Serizawa, T, Striegel, S, Tamura, M, Ueda, A, Vanderspek, R, Vievard, S, Winn, J N
• Format: Article
• Language: English
• Subjects: Extrasolar planets; Ground-based observation; Infrared instruments; Interiors; Orbits; Planetary evolution; Red dwarf stars; Statistical analysis; Terrestrial planets
• ISSN: 2331-8422

Sub-Neptunes with \(2-3R_\oplus\) are intermediate in size between rocky planets and Neptune-sized planets. The orbital properties and bulk compositions of transiting sub-Neptunes provide clues to the formation and evolution of close-in small planets. In this paper, we present the discovery and follow-up of four sub-Neptunes orbiting M dwarfs (TOI-782, TOI-1448, TOI-2120, and TOI-2406), three of which were newly validated by ground-based follow-up observations and statistical analyses. TOI-782 b, TOI-1448 b, TOI-2120 b, and TOI-2406 b have radii of \(R_\mathrm{p} = 2.740^{+0.082}_{-0.079}\,R_\oplus\), \(2.769^{+0.073}_{-0.068}\,R_\oplus\), \(2.120\pm0.067\,R_\oplus\), and \(2.830^{+0.068}_{-0.066}\,R_\oplus\) and orbital periods of \(P = 8.02\), \(8.11\), \(5.80\), and \(3.08\)\,days, respectively. Doppler monitoring with Subaru/InfraRed Doppler instrument led to 2\(\sigma\) upper limits on the masses of \(