A Caltech Library Service

The Generation of the Distant Kuiper Belt by Planet Nine from an Initially Broad Perihelion Distribution

Khain, Tali and Batygin, Konstantin and Brown, Michael E. (2018) The Generation of the Distant Kuiper Belt by Planet Nine from an Initially Broad Perihelion Distribution. Astronomical Journal, 155 (6). Art. No. 250. ISSN 1538-3881. doi:10.3847/1538-3881/aac212.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Accepted Version
See Usage Policy.


Use this Persistent URL to link to this item:


The observation that the orbits of long-period Kuiper Belt objects (KBOs) are anomalously clustered in physical space has recently prompted the Planet Nine hypothesis—the proposed existence of a distant and eccentric planetary member of our solar system. Within the framework of this model, a Neptune-like perturber sculpts the orbital distribution of distant KBOs through a complex interplay of resonant and secular effects, such that in addition to perihelion-circulating objects, the surviving orbits get organized into apsidally aligned and anti-aligned configurations with respect to Planet Nine's orbit. In this work, we investigate the role of Kuiper Belt initial conditions on the evolution of the outer solar system using numerical simulations. Intriguingly, we find that the final perihelion distance distribution depends strongly on the primordial state of the system, and we demonstrate that a bimodal structure corresponding to the existence of both aligned and anti-aligned clusters is only reproduced if the initial perihelion distribution is assumed to extend well beyond ~36 au. The bimodality in the final perihelion distance distribution is due to the existence of permanently stable objects, with the lower perihelion peak corresponding to the anti-aligned orbits and the higher perihelion peak corresponding to the aligned orbits. We identify the mechanisms that enable the persistent stability of these objects and locate the regions of phase space in which they reside. The obtained results contextualize the Planet Nine hypothesis within the broader narrative of solar system formation and offer further insight into the observational search for Planet Nine.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Khain, Tali0000-0001-7721-6457
Batygin, Konstantin0000-0002-7094-7908
Brown, Michael E.0000-0002-8255-0545
Additional Information:© 2018 The American Astronomical Society. Received 2018 January 17; revised 2018 April 29; accepted 2018 April 30; published 2018 May 25. We thank Elizabeth Bailey, Christopher Spalding, and Juliette Becker for useful conversations, and Fred Adams for a careful review of the draft. We thank the anonymous referee for valuable comments that led to the improvement of the manuscript. T.K. is grateful to the Johnson and Johnson WAVE Fellowship for funding as well as to the Caltech Student-Faculty Program for their support of this work. K.B. acknowledges the generous support of the David and Lucile Packard Foundation.
Group:Astronomy Department
Funding AgencyGrant Number
Johnson and JohnsonUNSPECIFIED
Caltech Summer Undergraduate Research Fellowship (SURF)UNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
Subject Keywords:celestial mechanics – Kuiper belt: general – planets and satellites: dynamical evolution and stability
Issue or Number:6
Record Number:CaltechAUTHORS:20180525-102419749
Persistent URL:
Official Citation:Tali Khain et al 2018 AJ 155 250
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:86622
Deposited By: Tony Diaz
Deposited On:25 May 2018 17:58
Last Modified:15 Nov 2021 20:40

Repository Staff Only: item control page