Radial distribution of distant trans-Neptunian objects points to Sun’s formation in a stellar cluster

The cluster_2 simulation of Nesvorný et al. (2023) readily generates detached orbits akin to the assumed Planet Nine orbit, whereas cluster_1 does not, underscoring the necessity of a relatively densely populated stellar environment for self-consistently achieving the assumed Planet Nine orbital parameters.

“While the cluster_2 simulation of Nesvorný et al. (2023) readily generates detached orbits akin to the one we assumed for P9, the cluster_1 simulation-which is characterized by weaker stellar perturbations-does not. 4 This discrepancy underscores the necessity of a relatively densely populated stellar environment for self-consistently achieving the orbital parameters we assume for P9.”

The parameters necessary to match the data in Nesvorný et al. (2023) are close to the upper limit of the allowed range imposed by the dynamical structure of the cold classical belt.

“the parameters necessary to match the data are close to the upper limit of the allowed range.”

The Planet Nine-free cluster_2 simulation of Nesvorný et al. (2023) includes all physical effects described in Section 2 with nearly identical implementation and represents the current benchmark for post-nebular evolution, previously validated against the distribution of high-q trans-Neptunian objects.

“As a null hypothesis, we considered the P9-free clus-ter_2 simulation of Nesvorný et al. (2023).Despite having been conducted with a different integrator, this simulation includes all of the physical effects described in Section 2, with nearly identical implementation.Moreover, the Nesvorný et al. (2023) model, previously validated against the distribution of high-q TNOs, represents the current”

Any alternative to P9 that aims to explain this population must invoke active perturbations beyond those accounted for in calculations of Nesvorný et al. (2023).

“any alternative to P9 that aims to explain this population must invoke active perturbations beyond those accounted for in calculations of Nesvorný et al. (2023).”