Discovery of a hot, transiting, Earth-sized planet and a second temperate, non-transiting planet around the M4 dwarf GJ 3473 (TOI-488)

October 2020 • 2020A&A...642A.236K

Authors • Kemmer, J. • Stock, S. • Kossakowski, D. • Kaminski, A. • Molaverdikhani, K. • Schlecker, M. • Caballero, J. A. • Amado, P. J. • Astudillo-Defru, N. • Bonfils, X. • Ciardi, D. • Collins, K. A. • Espinoza, N. • Fukui, A. • Hirano, T. • Jenkins, J. M. • Latham, D. W. • Matthews, E. C. • Narita, N. • Pallé, E. • Parviainen, H. • Quirrenbach, A. • Reiners, A. • Ribas, I. • Ricker, G. • Schlieder, J. E. • Seager, S. • Vanderspek, R. • Winn, J. N. • Almenara, J. M. • Béjar, V. J. S. • Bluhm, P. • Bouchy, F. • Boyd, P. • Christiansen, J. L. • Cifuentes, C. • Cloutier, R. • Collins, K. I. • Cortés-Contreras, M. • Crossfield, I. J. M. • Crouzet, N. • de Leon, J. P. • Della-Rose, D. D. • Delfosse, X. • Dreizler, S. • Esparza-Borges, E. • Essack, Z. • Forveille, Th. • Figueira, P. • Galadí-Enríquez, D. • Gan, T. • Glidden, A. • Gonzales, E. J. • Guerra, P. • Harakawa, H. • Hatzes, A. P. • Henning, Th. • Herrero, E. • Hodapp, K. • Hori, Y. • Howell, S. B. • Ikoma, M. • Isogai, K. • Jeffers, S. V. • Kürster, M. • Kawauchi, K. • Kimura, T. • Klagyivik, P. • Kotani, T. • Kurokawa, T. • Kusakabe, N. • Kuzuhara, M. • Lafarga, M. • Livingston, J. H. • Luque, R. • Matson, R. • Morales, J. C. • Mori, M. • Muirhead, P. S. • Murgas, F. • Nishikawa, J. • Nishiumi, T. • Omiya, M. • Reffert, S. • Rodríguez López, C. • Santos, N. C. • Schöfer, P. • Schwarz, R. P. • Shiao, B. • Tamura, M. • Terada, Y. • Twicken, J. D. • Ueda, A. • Vievard, S. • Watanabe, N. • Zechmeister, M.

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, M_b = 1.86 ± 0.30 M_⊕, and radius, R_b = 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, M_c sin i = 7.41 ± 0.91 M_⊕, and orbital period, P_c = 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.

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Links

• PREPRINT http://arxiv.org/abs/2009.10432
• POSTSCRIPT https://www.aanda.org/10.1051/0004-6361/202038967/postscript
• ELECTR https://doi.org/10.1051%2F0004-6361%2F202038967
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2020A%26A...642A.236K
• PDF https://www.aanda.org/10.1051/0004-6361/202038967/pdf
• DATA http://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/642/A236
• DATA http://archive.eso.org/bin/ads2eso?2020A%26A...642A.236K
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• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2020A%26A...642A.236K
• DATA https://irsa.ipac.caltech.edu/bibdata/2020/K/2020A&A...642A.236K.html
• DATA http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?type=REFERENCE&bibcode=2020arXiv200910432K