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.
CURVES
DYNAMICS
TERRESTRIAL PLANETS
MASS
PHOTOMETRY
MIGRATION
SUPER-EARTHS
ALGORITHM
SPECTRAL-ANALYSIS
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
University of La Laguna
Instituto de Astrofísica de Canarias
Anders Erikson
German Aerospace Center (DLR)
Massimiliano Esposito
Technische Universität Berlin
Thüringer Landessternwarte Tautenburg
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
Instituto de Astrofísica de Canarias
University of La Laguna
Maria Hjorth
Aarhus University
Petr Kabath
Czech Academy of Sciences
Emil Knudstrup
Aarhus University
Mikkel N. Lund
Aarhus University
Suvrath Mahadevan
Pennsylvania State University
Center for Exoplanets and Habitable Worlds
Savita Mathur
Instituto de Astrofísica de Canarias
University of La Laguna
Pilar Montanes Rodriguez
University of La Laguna
Instituto de Astrofísica de Canarias
Felipe Murgas
University of La Laguna
Instituto de Astrofísica de Canarias
Norio Narita
National Institutes of Natural Sciences
Japan Science and Technology Agency
Instituto de Astrofísica de Canarias
David Nespral
University of La Laguna
Instituto de Astrofísica de Canarias
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
Freie Universität Berlin
German Aerospace Center (DLR)
Technische Universität Berlin
Seth Redfield
Wesleyan University
Ignasi Ribas
Spanish National Research Council (CSIC)
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
Marek Skarka
Masaryk University
Czech Academy of Sciences
Alexis M. S. Smith
German Aerospace Center (DLR)
Jan Subjak
Charles University
Czech Academy of Sciences
Vincent Van Eylen
Princeton University
University College London (UCL)
Astronomical Journal
0004-6256 (ISSN) 1538-3881 (eISSN)
Vol. 159 3 120Subject Categories (SSIF 2011)
Aerospace Engineering
Astronomy, Astrophysics and Cosmology
Other Physics Topics
DOI
10.3847/1538-3881/ab66c9