Discovery of a hot, transiting, Earth-sized planet and a second temperate, non-transiting planet around the M4 dwarf GJ 3473 (TOI-488)
Creators: name: Kemmer, J.
name: Stock, S.
name: Kossakowski, D.
name: Kaminski, A.
name: Molaverdikhani, K.
name: Schlecker, M.
name: Caballero, J. A.
name: Amado, P. J.
name: Astudillo-Defru, N.
name: Bonfils, X.
name: Ciardi, D.
name: Collins, K. A.
name: Espinoza, N.
name: Fukui, A.
name: Hirano, T.
name: Jenkins, J. M.
name: Latham, D. W.
name: Matthews, E. C.
name: Narita, N.
name: Pallé, E.
name: Parviainen, H.
name: Quirrenbach, A.
name: Reiners, A.
name: Ribas, I.
name: Ricker, G.
name: Schlieder, J. E.
name: Seager, S.
name: V, R.
name: Winn, J. N.
name: Almenara, J. M.
name: Béjar, V. J. S.
name: Bluhm, P.
name: Bouchy, F.
name: Boyd, P.
name: Christiansen, J. L.
name: Cifuentes, C.
name: Cloutier, R.
name: Collins, K. I.
name: Cortés-Contreras, M.
name: Crossfield, I. J M.
name: Crouzet, N.
name: de Leon, J. P.
name: Della-Rose, D. D.
name: Delfosse, X.
name: Dreizler, S.
name: Esparza-Borges, E.
name: Essack, Z.
name: Forveille, Th.
name: Figueira, P.
name: Galadí-Enríquez, D.
name: Gan, T.
name: Glidden, A.
name: Gonzales, E. J.
name: Guerra, P.
name: Harakawa, H.
name: Hatzes, A. P.
name: Henning, Th.
name: Herrero, E.
name: Hodapp, K.
name: Hori, Y.
name: Howell, S. B.
name: Ikoma, M.
name: Isogai, K.
name: Jeffers, S. V.
name: Kürster, M.
name: Kawauchi, K.
name: Kimura, T.
name: Klagyivik, P.
name: Kotani, T.
name: Kurokawa, T.
name: Kusakabe, N.
name: Kuzuhara, M.
name: Lafarga, M.
name: Livingston, J. H.
name: Luque, R.
name: Matson, R.
name: Morales, J. C.
name: Mori, M.
name: Muirhead, P. S.
name: Murgas, F.
name: Nishikawa, J.
name: Nishiumi, T.
name: Omiya, M.
name: Reffert, S.
name: López, C. Rodríguez
name: Santos, N. C.
name: Schöfer, P.
name: Schwarz, R. P.
name: Shiao, B.
name: Tamura, M.
name: Terada, Y.
name: Twicken, J. D.
name: Ueda, A.
name: Vievard, S.
name: Watanabe, N.
name: Zechmeister, M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present the confirmation and characterisation of GJ 3473 b (G 50--16, TOI-488.01), a hot Earth-sized planet orbiting an M4 dwarf star, whose transiting signal ($P=1.1980035\pm0.0000018\mathrm{\,d}$) was first detected by the Transiting Exoplanet Survey Satellite (TESS). Through a joint modelling of follow-up radial velocity observations with CARMENES, IRD, and HARPS together with extensive ground-based photometric follow-up observations with LCOGT, MuSCAT, and MuSCAT2, we determined a precise planetary mass, $M_b = 1.86\pm0.30\,\mathrm{M_\oplus},$ and radius, $R_b = {1.264\pm0.050}\,\mathrm{R_\oplus}$. Additionally, we report the discovery of a second, temperate, non-transiting planet in the system, GJ 3473 c, which has a minimum mass, $M_c \sin{i} = {7.41\pm0.91}\,\mathrm{M_\oplus,}$ and orbital period, $P_c={15.509\pm0.033}\,\mathrm{d}$. The inner planet of the system, GJ 3473 b, is one of the hottest transiting Earth-sized planets known thus far, accompanied by a dynamical mass measurement, which makes it a particularly attractive target for thermal emission spectroscopy.
description: 21 pages; accepted for publication in A&amp;A