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, Galactic Astrophysics

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, Galactic Astrophysics

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 1807-1823

Exoplanets from space – CHEOPS and PLATO, ESA’s next two projects

Swedish National Space Board, 2017-01-01 -- 2022-12-31.

Subject Categories

Astronomy, Astrophysics and Cosmology

Roots

Basic sciences

DOI

10.1093/mnras/sty2760

More information

Latest update

5/14/2020