Discovery of a hot, transiting, Earth-sized planet and a second temperate, non-transiting planet around the M4 dwarf GJ 3473 (TOI-488)
Kuzuhara, M.; Tamura, M.; Bouchy, F.; Amado, P. J.; Caballero, J. A.; Pallé, E.; Reiners, A.; Ribas, I.; Quirrenbach, A.; Béjar, V. J. S.; Kaminski, A.; Kürster, M.; Morales, J. C.; Zechmeister, M.; Cortés-Contreras, M.; Dreizler, S.; Jeffers, S. V.; Lafarga, M.; Hirano, T.; Hatzes, A. P.; Narita, N.; Winn, J. N.; Henning, Th.; Klagyivik, P.; Kimura, T.; Galadí-Enríquez, D.; Bonfils, X.; Collins, K. A.; Collins, K. I.; Jenkins, J. M.; Luque, R.; Santos, N. C.; Seager, S.; Twicken, J. D.; Figueira, P.; Molaverdikhani, K.; Almenara, J. M.; Delfosse, X.; Latham, D. W.; Ricker, G.; Schwarz, R. P.; Vanderspek, R.; Esparza-Borges, E.; Murgas, F.; Fukui, A.; Crouzet, N.; Parviainen, H.; Watanabe, N.; Kusakabe, N.; Mori, M.; Terada, Y.; de Leon, J. P.; Nishiumi, T.; Stock, S.; Herrero, E.; Kemmer, J.; Schlecker, M.; Reffert, S.; Cifuentes, C.; Crossfield, I. J. M.; Espinoza, N.; Astudillo-Defru, N.; Kossakowski, D.; Bluhm, P.; Guerra, P.; Rodríguez López, C.; Schöfer, P.; Howell, S. B.; Matthews, E. C.; Cloutier, R.; Essack, Z.; Schlieder, J. E.; Boyd, P.; Christiansen, J. L.; Isogai, K.; Livingston, J. H.; Gan, T.; Gonzales, E. J.; Kawauchi, K.; Harakawa, H.; Hodapp, K.; Hori, Y.; Ikoma, M.; Kotani, T.; Nishikawa, J.; Omiya, M.; Ueda, A.; Vievard, S.; Shiao, B.; Kurokawa, T.; Ciardi, D.; Matson, R.; Glidden, A.; Della-Rose, D. D.; Forveille, Th.; Muirhead, P. S.
Germany, Spain, Chile, France, United States, Japan, Switzerland, Netherlands, Portugal, China
Abstract
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 ± 0.0000018 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, Mb = 1.86 ± 0.30 M⊕, and radius, Rb = 1.264 ± 0.050 R⊕. Additionally, we report the discovery of a second, temperate, non-transiting planet in the system, GJ 3473 c, which has a minimum mass, Mc sin i = 7.41 ± 0.91 M⊕, and orbital period, Pc = 15.509 ± 0.033 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.
RV data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/642/A236