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.

ALGORITHM

DYNAMICS

CURVES

SUPER-EARTHS

MIGRATION

PHOTOMETRY

TERRESTRIAL PLANETS

MASS

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

Instituto Astrofisico de Canarias

University of La Laguna

John H. Livingston

University of Tokyo

Teruyuki Hirano

Tokyo Institute of Technology

Roi Alonso Sobrino

Instituto Astrofisico de Canarias

University of La Laguna

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 Astrofisico 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, Galactic Astrophysics

Akihiko Fukui

National Institutes of Natural Sciences

Davide Gandolfi

University of Turin

Iskra Georgieva

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Galactic Astrophysics

Luca Gonzalez Cuesta

Instituto Astrofisico 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 Astrofisico 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

Penn State Astrobiol Res Ctr

Pennsylvania State University

Ctr Exoplanets & Habitable Worlds

Savita Mathur

University of La Laguna

Instituto Astrofisico de Canarias

Pilar Montanes Rodriguez

Instituto Astrofisico de Canarias

University of La Laguna

Felipe Murgas

Instituto Astrofisico de Canarias

University of La Laguna

Norio Narita

Japan Science and Technology Agency

National Institutes of Natural Sciences

Instituto Astrofisico de Canarias

David Nespral

University of La Laguna

Instituto Astrofisico de Canarias

Prajwal Niraula

MIT, Dept Earth Atmospher & Planetary Sci, 77 Massachusetts Ave

Enric Palle

Instituto Astrofisico de Canarias

University of La Laguna

Martin Paetzold

University of Cologne

Carina M. Persson

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics, Galactic Astrophysics

Jorge Prieto-Arranz

University of La Laguna

Instituto Astrofisico de Canarias

Heike Rauer

Technische Universität Berlin

German Aerospace Center (DLR)

FU Berlin

Seth Redfield

Wesleyan University

Ignasi Ribas

Spanish National Research Council (CSIC)

Institute of Space Studies of Catalonia (IEEC)

Marek Skarka

Czech Academy of Sciences

Masaryk University

Alexis M. S. Smith

German Aerospace Center (DLR)

Jan Subjak

Czech Academy of Sciences

Charles Univ Prague

Vincent Van Eylen

University College London (UCL)

Princeton University

Astronomical Journal

0004-6256 (ISSN) 1538-3881 (eISSN)

Vol. 159 3 120

Subject Categories

Aerospace Engineering

Astronomy, Astrophysics and Cosmology

Other Physics Topics

DOI

10.3847/1538-3881/ab66c9

More information

Latest update

6/3/2020 6