English

A Robust Launching Mechanism for Freely-Floating Planets from Host Stars with Close-in Planets

Earth and Planetary Astrophysics 2026-04-22 v2

Abstract

Secular perturbations from binary stars and distant massive planets can drive cold planets onto nearly parabolic orbits with pericenter passages extremely close to their host stars. Meanwhile, short-period super-Earths are frequently observed around nearby stars. Gravitational scattering between these two distinct populations can lead to substantial orbital energy exchange, liberating some intruders from the gravitational confinement of their host systems. This process offers a robust formation channel for a subset of the abundant freely floating planet population. It may also significantly perturb the original orbits of close-in planets, induce collisional trajectories between close-in planets and their host stars, and disrupt the dynamical evolution of cold planets toward close stellar encounters.

Keywords

Cite

@article{arxiv.2601.09835,
  title  = {A Robust Launching Mechanism for Freely-Floating Planets from Host Stars with Close-in Planets},
  author = {Xiaochen Zheng and Zhuoya Cao and Shigeru Ida and Douglas N. C. Lin and Shude Mao},
  journal= {arXiv preprint arXiv:2601.09835},
  year   = {2026}
}

Comments

26 pages, 9 figures. Accepted by the Astrophysical Journal