A Caltech Library Service

The planet nine hypothesis

Batygin, Konstantin and Adams, Fred C. and Brown, Michael E. and Becker, Juliette C. (2019) The planet nine hypothesis. Physics Reports, 805 . pp. 1-53. ISSN 0370-1573. doi:10.1016/j.physrep.2019.01.009.

[img] PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


Over the course of the past two decades, observational surveys have unveiled the intricate orbital structure of the Kuiper Belt, a field of icy bodies orbiting the Sun beyond Neptune. In addition to a host of readily-predictable orbital behavior, the emerging census of trans-Neptunian objects displays dynamical phenomena that cannot be accounted for by interactions with the known eight-planet solar system alone. Specifically, explanations for the observed physical clustering of orbits with semi-major axes in excess of ∼250AU, the detachment of perihelia of select Kuiper belt objects from Neptune, as well as the dynamical origin of highly inclined/retrograde long-period orbits remain elusive within the context of the classical view of the solar system. This newly outlined dynamical architecture of the distant solar system points to the existence of a new planet with mass of m_g ∼5−10M⊕, residing on a moderately inclined orbit (i_g∼15−25deg) with semi-major axis a_g∼400−800AU and eccentricity between e_g∼0.2−0.5. This paper reviews the observational motivation, dynamical constraints, and prospects for detection of this proposed object known as Planet Nine.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Batygin, Konstantin0000-0002-7094-7908
Adams, Fred C.0000-0002-8167-1767
Brown, Michael E.0000-0002-8255-0545
Becker, Juliette C.0000-0002-7733-4522
Additional Information:© 2019 Elsevier B.V. Received 5 November 2018, Accepted 30 January 2019, Available online 10 February 2019.
Group:Astronomy Department
Funding AgencyGrant Number
David and Lucile Packard FoundationUNSPECIFIED
Alfred P. Sloan FoundationUNSPECIFIED
Record Number:CaltechAUTHORS:20190211-091552305
Persistent URL:
Official Citation:Konstantin Batygin, Fred C. Adams, Michael E. Brown, Juliette C. Becker, The planet nine hypothesis, Physics Reports, Volume 805, 2019, Pages 1-53, ISSN 0370-1573, (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:92824
Deposited By: Tony Diaz
Deposited On:12 Feb 2019 22:22
Last Modified:16 Nov 2021 03:53

Repository Staff Only: item control page