In:
Astronomy & Astrophysics, EDP Sciences, Vol. 628 ( 2019-8), p. A39-
Abstract:
We report the detection of a transiting Earth-size planet around GJ 357, a nearby M2.5 V star, using data from the Transiting Exoplanet Survey Satellite (TESS). GJ 357 b (TOI-562.01) is a transiting, hot, Earth-sized planet ( T eq = 525 ± 11 K) with a radius of R b = 1.217 ± 0.084 R ⊕ and an orbital period of P b = 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 M b = 1.84 ± 0.31 M ⊕ . 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 M c = 3.40 ± 0.46 M ⊕ in a 9.12 d orbit, and GJ 357 d, with a minimum mass of M d = 6.1 ± 1.0 M ⊕ in a 55.7 d orbit inside the habitable zone. The host is relatively inactive and exhibits a photometric rotation period of P rot = 78 ± 2 d. GJ 357 b isto 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.
Type of Medium:
Online Resource
ISSN:
0004-6361
,
1432-0746
DOI:
10.1051/0004-6361/201935801
Language:
English
Publisher:
EDP Sciences
Publication Date:
2019
detail.hit.zdb_id:
1458466-9
SSG:
16,12
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