An ultra-short-period super-Earth with an extremely high density and an outer companion
Journal article, 2024
We present the discovery and characterization of a new multi-planetary system around the Sun-like star K2-360 (EPIC 201595106). K2-360 was first identified in K2 photometry as the host of an ultra-short-period (USP) planet candidate with a period of 0.88 d. We obtained follow-up transit photometry, confirming the star as the host of the signal. High precision radial velocity measurements from HARPS and HARPS-N confirm the transiting USP planet and reveal the existence of an outer (non-transiting) planet with an orbital period of ∼10 d. We measure a mass of 7.67±0.75 M⊕ and a radius of 1.57±0.08 R⊕ for the transiting planet, yielding a high mean density of 11±2 g cm-3, making it the densest well-characterized USP super-Earth discovered to date. We measure a minimum mass of 15.2±1.8 M⊕ for the outer planet, and explore a migration formation pathway via the von Zeipel–Kozai–Lidov (ZKL) mechanism and tidal dissipation.
Author
J.H. Livingston
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
National Institutes of Natural Sciences
D. Gandolfi
University of Turin
Alessandro A. Trani
Research Center for the Early Universe
Niels Bohr Institute
Okinawa Institute of Science and Technology Graduate University
Mahesh Herath
McGill University
O. Barragán
University of Oxford
A. Hatzes
Thüringer Landessternwarte Tautenburg
R. Luque
University of Chicago
A. Fukui
University of Tokyo
G. Nowak
Instituto de Astrofísica de Canarias
Nicolaus Copernicus University
University of La Laguna
Enric Palle
Instituto de Astrofísica de Canarias
University of La Laguna
Coel Hellier
Keele University
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Jerome P. De Leon
University of Tokyo
T. Hirano
The Graduate University for Advanced Studies (SOKENDAI)
National Institutes of Natural Sciences
National Astronomical Observatory of Japan
Norio Narita
University of Tokyo
Simon Albrecht
Aarhus University
Fei Dai
California Institute of Technology (Caltech)
University of Hawaii
H. Deeg
Instituto de Astrofísica de Canarias
University of La Laguna
Vincent Van Eylen
University College London (UCL)
Judith Korth
Lund University
Motohide Tamura
University of Tokyo
National Institutes of Natural Sciences
National Astronomical Observatory of Japan
Scientific Reports
2045-2322 (ISSN) 20452322 (eISSN)
Vol. 14 1 27219Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.1038/s41598-024-76490-y
PubMed
39516227