It Takes Two Planets in Resonance to Tango around K2-146
Artikel i vetenskaplig tidskrift, 2020

K2-146 is a cool, 0.358 M⊙ 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 R⊕ and a mass of 5.6 ± 0.7 M⊕ , whereas K2-146 c has a radius of 2.59+1.81−0.39 R⊕ and a mass of 7.1 ± 0.9 M⊕ . 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.

Författare

K. W.F. Lam

J. Korth

Kento Masuda

Szilard Csizmadia

Philipp Eigmüller

Gudmur Kári stefánsson

M. Endl

S. Albrecht

Paul Robertson

Rafael Luque

J. Livingston

Teruyuki Hirano

Roi Alonso Sobrino

Oscar Barragan

J. Cabrera

Ilaria Carleo

Alexander Chaushev

W. D. Cochran

F. Dai

Jerome de Leon

H. Deeg

A. Erikson

M. Esposito

Malcolm Fridlund

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

A. Fukui

D. Gandolfi

Iskra Georgieva

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Extragalaktisk astrofysik

Lucá Gonzalez Cuesta

Sascha Grziwa

Eike W. Guenther

Artie P. Hatzes

Diego Hidalgo

Maria Hjorth

P. Kabath

E. Knudstrup

Mikkel N. Lund

Suvrath Mahadevan

Savita Mathur

Pilar Montanes Rodriguez

Felipe Murgas

Norio Narita

D. Nespral

P. Niraula

Enric Palle

Martin Pätzold

Carina Persson

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

Jorge Prieto-Arranz

H. Rauer

S. Redfield

I Ribas

Marek Skarka

Alexis M.S. Smith

J. Subjak

Vincent Van Eylen

Astronomical Journal

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

Vol. 159 120-

Förlängning: Exoplanets from space -CHEOPS and PLATO ESA's next two projects (Phase 2)

Rymdstyrelsen (65/19), 2020-01-01 -- 2022-12-31.

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

DOI

10.3847/1538-3881/ab66c9

Mer information

Skapat

2021-06-08