Star Cluster Ecology VIII. -- Dynamically Forming S-Type and αCentauri-like Systems

@misc{hochart2026star,
  title = {{Star Cluster Ecology VIII. -- Dynamically Forming S-Type and $α$Centauri-like Systems}},
  author = {Erwan Hochart and Simon Portegies Zwart},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.13127},
  eprint = {2610.13127},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.13127},
}

TY  - UNPB
TI  - Star Cluster Ecology VIII. -- Dynamically Forming S-Type and αCentauri-like Systems
AU  - Erwan Hochart
AU  - Simon Portegies Zwart
PY  - 2026
DA  - 2026/10/09
PB  - arXiv
DO  - 10.48550/arxiv.2610.13127
UR  - https://arxiv.org/abs/2610.13127
AB  - Aims: To analyse the impact of dynamically formed binaries emerging naturally from various star cluster environments on already established planetary systems. Methods: Numerical simulations replicating the star-forming region NGC 1333 are conducted. We consider three models, each using identical cluster realisations and simulation parameters. The cluster itself is initially sub-virial and fractally distributed. Model~A assumes planetary systems are initially in mean motion resonance. In Model~B, the same planetary systems are moved out of resonance, but remain intrinsically stable. Finally, Model~C removes all planets from the simulation. Ten independent realisations are integrated per model until 30 Myr. Results: Dynamically formed binaries emerge at similar rates across models, indicating planets play little role in their formation. We also find a higher production rate of wide binaries compared to previous numerical studies which we attribute to the sub-virial and sub-clustered initial conditions. S-type and binary S-type planetary systems naturally emerge in our simulations, while P-type systems are rare. For Model~A, the fraction of S-type or binary S-type systems is f_{\rm S}=0.02 and $f_{\rm Bin,\, S}=0.05, respectively. Rogue planets originating from a binary system are ejected with a substantially larger velocity than those around singletons. Planet-star collisions and planet capture events occur disproportionately within binary systems. Finally, several \alphaCentauri-like systems emerge in our simulations, suggesting that the nearest stellar system to the Sun may have a dynamical origin.
ER  -