K2-141 b : A 5- M _⊗ super-Earth transiting a K7 v star every 6.7 h

Summary, in English

We report on the discovery of K2-141 b (EPIC 246393474 b), an ultra-short-period super-Earth on a 6.7 h orbit transiting an active K7 V star based on data from K2 campaign 12. We confirmed the planet's existence and measured its mass with a series of follow-up observations: seeing-limited Muscat imaging, NESSI high-resolution speckle observations, and FIES and HARPS high-precision radial-velocity monitoring. K2-141 b has a mass of 5.31 ± 0.46 M_⊗ and radius of 1.54_-0.09^+0.10 R_⊗, yielding a mean density of 8.00_-1.45^+1.83 g cm^-3 and suggesting a rocky-iron composition. Models indicate that iron cannot exceed ∼70% of the total mass. With an orbital period of only 6.7 h, K2-141 b is the shortest-period planet known to date with a precisely determined mass.

• Author: O. Barragán; D. Gandolfi; F. Dai; J. Livingston; C. M. Persson; T. Hirano; N. Narita; Sz Csizmadia; J. N. Winn; D. Nespral; J. Prieto-Arranz; A. M.S. Smith; G. Nowak; S. Albrecht; G. Antoniciello; A. Bo Justesen; J. Cabrera; W. D. Cochran; H. Deeg; Ph Eigmuller; M. Endl; A. Erikson; M. Fridlund; A. Fukui; S. Grziwa; E. Guenther; A. P. Hatzes; D. Hidalgo; M. C. Johnson; J. Korth; E. Palle; M. Patzold; H. Rauer; Y. Tanaka; V. Van Eylen
• Publishing year: 2018-04-01
• Language: English
• Publication/Series: Astronomy and Astrophysics
• Volume: 612
• Links: http://dx.doi.org/10.1051/0004-6361/201732217
• Document type: Journal article
• Publisher: EDP Sciences
• Keywords: Planetary systems; Planets and satellites: individual: EPIC 246393474 b; Stars: fundamental parameters; Stars: individual: EPIC 246393474; Techniques: photometric; Techniques: radial velocities
• Status: Published
• ISBN/ISSN/Other: ISSN: 0004-6361