A low-eccentricity migration pathway for a 13-h-period Earth analogue in a four-planet system
Artikel i vetenskaplig tidskrift, 2022

It is commonly accepted that exoplanets with orbital periods shorter than one day, also known as ultra-short-period (USP) planets, formed further out within their natal protoplanetary disks before migrating to their current-day orbits via dynamical interactions. One of the most accepted theories suggests a violent scenario involving high-eccentricity migration followed by tidal circularization. Here we present the discovery of a four-planet system orbiting the bright (V = 10.5) K6 dwarf star TOI-500. The innermost planet is a transiting, Earth-sized USP planet with an orbital period of ~13 hours, a mass of 1.42 ± 0.18 M⊕, a radius of 1.166−0.058+0.061R⊕ and a mean density of 4.89−0.88+1.03gcm−3. Via Doppler spectroscopy, we discovered that the system hosts 3 outer planets on nearly circular orbits with periods of 6.6, 26.2 and 61.3 days and minimum masses of 5.03 ± 0.41 M⊕, 33.12 ± 0.88 M⊕ and 15.05−1.11+1.12M⊕, respectively. The presence of both a USP planet and a low-mass object on a 6.6-day orbit indicates that the architecture of this system can be explained via a scenario in which the planets started on low-eccentricity orbits then moved inwards through a quasi-static secular migration. Our numerical simulations show that this migration channel can bring TOI-500 b to its current location in 2 Gyr, starting from an initial orbit of 0.02 au. TOI-500 is the first four-planet system known to host a USP Earth analogue whose current architecture can be explained via a non-violent migration scenario.

Författare

L. M. Serrano

Universita degli Studi di Torino

D. Gandolfi

Universita degli Studi di Torino

A. J. Mustill

Lunds universitet

O. Barragán

University of Oxford

Judith Korth

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Astronomi och plasmafysik 2

Fei Dai

California Institute of Technology (Caltech)

S. Redfield

Wesleyan University

C.W.M. Fridlund

Universiteit Leiden

K. W.F. Lam

Technische Universität Berlin

Matías R. Díaz

Universidad de Chile (UCH)

Las Campanas Observatory

S. Grziwa

Universität zu Köln

Karen A. Collins

Harvard-Smithsonian Center for Astrophysics

J.H. Livingston

University of Tokyo

William D. Cochran

The University of Texas at Austin

Coel Hellier

Keele University

Salvatore E. Bellomo

Universita degli Studi di Torino

T. Trifonov

Max-Planck-Gesellschaft

Sofijski universitet

F. Rodler

European Southern Observatory Santiago

Javier Alarcon

European Southern Observatory Santiago

Jon M. Jenkins

NASA Ames Research Center

D. W. Latham

Harvard-Smithsonian Center for Astrophysics

George R. Ricker

Massachusetts Institute of Technology (MIT)

S. Seager

Massachusetts Institute of Technology (MIT)

Roland Vanderspeck

Massachusetts Institute of Technology (MIT)

J. N. Winn

Princeton University

Simon Albrecht

Aarhus Universitet

Kevin I. Collins

George Mason University

Szilárd Csizmadia

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

Tansu Daylan

Massachusetts Institute of Technology (MIT)

H. Deeg

Instituto de Astrofísica de Canarias

Universidad de la Laguna

M. Esposito

Thüringer Landessternwarte Tautenburg

Michael Fausnaugh

Massachusetts Institute of Technology (MIT)

Iskra Georgieva

Universiteit Leiden

E. Goffo

Universita degli Studi di Torino

Thüringer Landessternwarte Tautenburg

E. W. Guenther

Thüringer Landessternwarte Tautenburg

A. Hatzes

Thüringer Landessternwarte Tautenburg

S.B. Howell

NASA Ames Research Center

Eric L.N. Jensen

Swarthmore College

R. Luque

Universidad de la Laguna

Instituto de Astrofísica de Canarias

A. Mann

The University of North Carolina at Chapel Hill

F. Murgas

Instituto de Astrofísica de Canarias

Universidad de la Laguna

H. L.M. Osborne

University College London (UCL)

Enric Palle

Universidad de la Laguna

Instituto de Astrofísica de Canarias

Carina Persson

Universiteit Leiden

Pamela Rowden

Royal Astronomical Society

Alexander Rudat

Massachusetts Institute of Technology (MIT)

Alexis M. S. Smith

Deutsches Zentrums für Luft- und Raumfahrt (DLR)

J. D. Twicken

SETI Institute

NASA Ames Research Center

Vincent Van Eylen

University College London (UCL)

C. Ziegler

Stephen F. Austin State University

Nature Astronomy

23973366 (eISSN)

Vol. In Press

Ämneskategorier

Astronomi, astrofysik och kosmologi

Annan fysik

Inbäddad systemteknik

DOI

10.1038/s41550-022-01641-y

Mer information

Senast uppdaterat

2022-05-12