A small team of planetary scientists from the California Institute of Technology, Université Côte d'Azur and Southwest Research Institute reports possible new evidence of Planet 9. They have published their paper on the arXiv preprint server, and it has been accepted for publication in The Astrophysical Journal Letters.
"The solar system's distant reaches exhibit a wealth of anomalous dynamical structure, hinting at the presence of a yet-undetected, massive trans-Neptunian body - Planet 9. Previous analyses have shown how orbital evolution induced by this object can explain the origins of a broad assortment of exotic orbits, ranging from those characterized by high perihelia to those with extreme inclinations. In this work, we shift the focus toward a more conventional class of TNOs, and consider the observed census of long-period, nearly planar, Neptune-crossing objects as a hitherto-unexplored probe of the Planet 9 hypothesis. To this end, we carry out comprehensive N−body simulations that self-consistently model gravitational perturbations from all giant planets, the Galactic tide, as well as passing stars, stemming from initial conditions that account for the primordial giant planet migration and sun's early evolution within a star cluster. Accounting for observational biases, our results reveal that the orbital architecture of this group of objects aligns closely with the predictions of the P9-inclusive model. In stark contrast, the P9-free scenario is statistically rejected at a ∼5σ confidence-level. Accordingly, this work introduces a new line of evidence supporting the existence of Planet 9 and further delineates a series of observational predictions poised for near-term resolution."
