It Takes Two Planets in Resonance to Tango around K2-146
Journal article, 2020
K2-146 is a cool, 0.358M dwarf that was found to host a mini-Neptune with a 2.67 day period. The planet exhibited strong transit timing variations (TTVs) of greater than 30 minutes, indicative of the presence of an additional object in the system. Here we report the discovery of the previously undetected outer planet in the system, K2-146 c, using additional photometric data. K2-146 c was found to have a grazing transit geometry and a 3.97 day period. The outer planet was only significantly detected in the latter K2 campaigns presumably because of precession of its orbital plane. The TTVs of K2-146 b and c were measured using observations spanning a baseline of almost 1200 days. We found strong anti -correlation in the TTVs, suggesting the two planets are gravitationally interacting. Our TTV and transit model analyses revealed that K2-146 b has a radius of 2.25 0.10 Re and a mass of 5.6 0.7 Me, whereas K2-146 c has a radius of 2.591 Re and a mass of 7.1 0.9 Me. The inner and outer planets likely have moderate eccentricities of e = 0.14 0.07 and 0.16 0.07, respectively. Long-term numerical integrations of the two -planet orbital solution show that it can be dynamically stable for at least 2 Myr. We show that the resonance angles of the planet pair are librating, which may be an indication that K2-146 b and c are in a 3:2 mean motion resonance. The orbital architecture of the system points to a possible convergent migration origin.
MASS
DYNAMICS
PHOTOMETRY
SPECTRAL-ANALYSIS
ALGORITHM
CURVES
TERRESTRIAL PLANETS
MIGRATION
SUPER-EARTHS
Author
Kristine W. F. Lam
Technische Universität Berlin
Judith Korth
University of Cologne
Kento Masuda
Princeton University
Szilard Csizmadia
German Aerospace Center (DLR)
Philipp Eigmueller
German Aerospace Center (DLR)
Gumundur Kari Stefansson
Pennsylvania State University
Michael Endl
The University of Texas at Austin
Simon Albrecht
Aarhus University
Paul Robertson
Pennsylvania State University
Rafael Luque
University of La Laguna
Instituto de Astrofísica de Canarias
John H. Livingston
University of Tokyo
Teruyuki Hirano
Tokyo Institute of Technology
Roi Alonso Sobrino
University of La Laguna
Instituto de Astrofísica de Canarias
Oscar Barragan
University of Oxford
Juan Cabrera
German Aerospace Center (DLR)
Ilaria Carleo
Wesleyan University
Alexander Chaushev
Technische Universität Berlin
William D. Cochran
The University of Texas at Austin
Fei Dai
Massachusetts Institute of Technology (MIT)
Princeton University
Jerome de Leon
University of Tokyo
Hans J. Deeg
Instituto de Astrofísica de Canarias
University of La Laguna
Anders Erikson
German Aerospace Center (DLR)
Massimiliano Esposito
Thüringer Landessternwarte Tautenburg
Technische Universität Berlin
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Akihiko Fukui
National Institutes of Natural Sciences
Davide Gandolfi
University of Turin
Iskra Georgieva
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Luca Gonzalez Cuesta
Instituto de Astrofísica de Canarias
University of La Laguna
Sascha Grziwa
University of Cologne
Eike W. Guenther
Thüringer Landessternwarte Tautenburg
Artie P. Hatzes
Thüringer Landessternwarte Tautenburg
Diego Hidalgo
University of La Laguna
Instituto de Astrofísica de Canarias
Maria Hjorth
Aarhus University
Petr Kabath
Czech Academy of Sciences
Emil Knudstrup
Aarhus University
Mikkel N. Lund
Aarhus University
Suvrath Mahadevan
Center for Exoplanets and Habitable Worlds
Pennsylvania State University
Savita Mathur
Instituto de Astrofísica de Canarias
University of La Laguna
Pilar Montanes Rodriguez
Instituto de Astrofísica de Canarias
University of La Laguna
Felipe Murgas
Instituto de Astrofísica de Canarias
University of La Laguna
Norio Narita
National Institutes of Natural Sciences
Instituto de Astrofísica de Canarias
Japan Science and Technology Agency
David Nespral
Instituto de Astrofísica de Canarias
University of La Laguna
Prajwal Niraula
Massachusetts Institute of Technology (MIT)
Enric Palle
Instituto de Astrofísica de Canarias
University of La Laguna
Martin Paetzold
University of Cologne
Carina Persson
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Jorge Prieto-Arranz
Instituto de Astrofísica de Canarias
University of La Laguna
Heike Rauer
Technische Universität Berlin
German Aerospace Center (DLR)
Freie Universität Berlin
Seth Redfield
Wesleyan University
Ignasi Ribas
Institute of Space Studies of Catalonia (IEEC)
Spanish National Research Council (CSIC)
Marek Skarka
Czech Academy of Sciences
Masaryk University
Alexis M. S. Smith
German Aerospace Center (DLR)
Jan Subjak
Czech Academy of Sciences
Charles University
Vincent Van Eylen
University College London (UCL)
Princeton University
Astronomical Journal
0004-6256 (ISSN) 1538-3881 (eISSN)
Vol. 159 3 120Subject Categories
Aerospace Engineering
Astronomy, Astrophysics and Cosmology
Other Physics Topics
DOI
10.3847/1538-3881/ab66c9