K2-140b and K2-180b - Characterization of a hot Jupiter and a mini-Neptune from the K2 mission
Journal article, 2019
We report the independent discovery and characterization of two K2 planets: K2-180b, a mini-Neptune-sized planet in an 8.9-d orbit transiting a V = 12.6 mag, metal-poor ([Fe/H] = -0.65 ± 0.10) K2V star in K2 campaign 5; K2-140b, a transiting hot Jupiter in a 6.6-d orbit around a V = 12.6 mag G6V ([Fe/H] = + 0.10 ± 0.10) star in K2 campaign 10. Our results are based on K2 time-series photometry combined with high-spatial resolution imaging and high-precision radial velocity measurements. We present the first mass measurement of K2-180b. K2-180b has a mass of Mp = 11.3 ± 1.9 M_Earth and a radius of Rp = 2.2 ± 0.1 R_Earth, yielding a mean density of ρp = 5.6 ± 1.9 g cm-3, suggesting a rocky composition. Given its radius, K2-180b is above the region of the so-called `planetary radius gap'. K2-180b is in addition not only one of the densest mini-Neptune-sized planets, but also one of the few mini-Neptune-sized planets known to transit a metal-poor star. We also constrain the planetary and orbital parameters of K2-140b and show that, given the currently available Doppler measurements, the eccentricity is consistent with zero, contrary to the results of a previous study.
planets and satellites: fundamental parameters
stars: individual: K2-180
stars: individual: K2-140
stars: fundamental parameters
techniques: photometric
techniques: radial velocities
Author
J. Korth
University of Cologne
Sz. Csizmadia
German Aerospace Center (DLR)
D. Gandolfi
University of Turin
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
M. Pätzold
University of Cologne
T. Hirano
Tokyo Institute of Technology
J. Livingston
Tokyo Institute of Technology
Carina Persson
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
H. J. Deeg
University of La Laguna
A.B. Justesen
Aarhus University
O. Barragan
University of Turin
S. Grziwa
University of Cologne
M. Endl
The University of Texas at Austin
R. Tronsgaard
Nordic Optical Telescope
F. Dai
Massachusetts Institute of Technology (MIT)
W. D. Cochran
The University of Texas at Austin
S. Albrecht
Aarhus University
R. Alonso
University of La Laguna
J. Cabrera
German Aerospace Center (DLR)
P.W. Cauley
Wesleyan University
F. Cusano
Istituto nazionale di astrofisica (INAF)
Ph Eigmüller
German Aerospace Center (DLR)
A. Erikson
German Aerospace Center (DLR)
M. Esposito
Thüringer Landessternwarte Tautenburg
E. W. Guenther
Thüringer Landessternwarte Tautenburg
A. P. Hatzes
Thüringer Landessternwarte Tautenburg
D. Hidalgo
University of La Laguna
M. Kuzuhara
National Institutes of Natural Sciences
P. Montañes
University of La Laguna
N.R. Napolitano
Istituto nazionale di astrofisica (INAF)
N. Narita
National Institutes of Natural Sciences
University of Tokyo
University of La Laguna
P. Niraula
Wesleyan University
D. Nespral
University of La Laguna
G. Nowak
University of La Laguna
E. Palle
University of La Laguna
C.E. Petrillo
University of Groningen
S. Redfield
Wesleyan University
J. Prieto-Arranz
University of La Laguna
H. Rauer
German Aerospace Center (DLR)
Technische Universität Berlin
Freie Universität Berlin
A. M. S. Smith
German Aerospace Center (DLR)
C. Tortora
University of Groningen
V. Van Eylen
Leiden University
J. N. Winn
Princeton University
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 482 2 1807-1823Exoplanets from space – CHEOPS and PLATO, ESA’s next two projects
Swedish National Space Board (174/18), 2017-01-01 -- 2022-12-31.
Subject Categories
Astronomy, Astrophysics and Cosmology
Roots
Basic sciences
DOI
10.1093/mnras/sty2760