학술논문
Planetary system around the nearby M dwarf GJ 357 including a transiting, hot, Earth-sized planet optimal for atmospheric characterization
Document Type
Working Paper
Author
Luque, R.; Pallé, E.; Kossakowski, D.; Dreizler, S.; Kemmer, J.; Espinoza, N.; Burt, J.; Anglada-Escudé, G.; Béjar, V. J. S.; Caballero, J. A.; Collins, K. A.; Collins, K. I.; Cortés-Contreras, M.; Díez-Alonso, E.; Feng, F.; Hatzes, A.; Hellier, C.; Henning, T.; Jeffers, S. V.; Kaltenegger, L.; Kürster, M.; Madden, J.; Molaverdikhani, K.; Montes, D.; Narita, N.; Nowak, G.; Ofir, A.; Oshagh, M.; Parviainen, H.; Quirrenbach, A.; Reffert, S.; Reiners, A.; Rodríguez-López, C.; Schlecker, M.; Stock, S.; Trifonov, T.; Winn, J. N.; Osorio, M. R. Zapatero; Zechmeister, M.; Amado, P. J.; Anderson, D. R.; Batalha, N. E.; Bauer, F. F.; Bluhm, P.; Burke, C. J.; Butler, R. P.; Caldwell, D. A.; Chen, G.; Crane, J. D.; Dragomir, D.; Dressing, C. D.; Dynes, S.; Jenkins, J. M.; Kaminski, A.; Klahr, H.; Kotani, T.; Lafarga, M.; Latham, D. W.; Lewin, P.; McDermott, S.; Montañés-Rodríguez, P.; Morales, J. C.; Murgas, F.; Nagel, E.; Pedraz, S.; Ribas, I.; Ricker, G. R.; Rowden, P.; Seager, S.; Shectman, S. A.; Tamura, M.; Teske, J.; Twicken, J. D.; Vanderspeck, R.; Wang, S. X.; Wohler, B.
Source
A&A 628, A39 (2019)
Subject
Language
Abstract
We report the detection of a transiting Earth-size planet around GJ 357, a nearby M2.5V star, using data from the Transiting Exoplanet Survey Satellite (TESS). GJ 357 b (TOI-562.01) is a transiting, hot, Earth-sized planet (Teq=525+-11 K) with a radius of Rb=1.217+-0.084 Re and an orbital period of Pb=3.93 d. Precise stellar radial velocities from CARMENES and PFS, as well as archival data from HIRES, UVES, and HARPS also display a 3.93-day periodicity, confirming the planetary nature and leading to a planetary mass of Mb=1.84+-0.31 Me. In addition to the radial velocity signal for GJ 357 b, more periodicities are present in the data indicating the presence of two further planets in the system: GJ 357 c, with a minimum mass of Mc=3.40+-0.46 Me in a 9.12 d orbit, and GJ 357 d, with a minimum mass of Md=6.1+-1.0 Me in a 55.7 d orbit inside the habitable zone. The host is relatively inactive and exhibits a photometric rotation period of Prot=78+-2 d. GJ 357 b is to date the second closest transiting planet to the Sun, making it a prime target for further investigations such as transmission spectroscopy. Therefore, GJ 357 b represents one of the best terrestrial planets suitable for atmospheric characterization with the upcoming JWST and ground-based ELTs.