Solar Obliquity Induced by Planet Nine

The six-degree obliquity of the sun suggests that either an asymmetry was present in the solar system’s formation environment, or an external torque has misaligned the angular momentum vectors of the sun and the planets.
However, the exact origin of this obliquity remains an open question. Batygin & Brown (2016) have recently shown that the physical alignment of distant Kuiper Belt orbits can be explained by a 5-20 Earth-mass planet on a distant, eccentric, and inclined orbit, with an approximate perihelion distance of ~250 AU.

Using an analytic model for secular interactions between Planet Nine and the remaining giant planets, here we show that a planet with similar parameters can naturally generate the observed obliquity as well as the specific pole position of the sun’s spin axis, from a nearly aligned initial state.

Thus, Planet Nine offers a testable explanation for the otherwise mysterious spin-orbit misalignment of the solar system.

Elizabeth Bailey, Konstantin Batygin, Michael E. Brown
(Submitted on 14 Jul 2016 (this version), latest version 20 Jul 2016 (v2))

Comments: 8 pages, 4 figures, submitted to AJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1607.03963 [astro-ph.EP] (or arXiv:1607.03963v1 [astro-ph.EP] for this version)
Submission history
From: Elizabeth Bailey ]
[v1] Thu, 14 Jul 2016 00:03:28 GMT (5282kb,D)
[v2] Wed, 20 Jul 2016 01:21:27 GMT (5238kb,D)
http://arxiv.org/abs/1607.03963v1