# On the dynamical evolution of the Orion Trapezium

## TL;DR

This paper uses observed velocities and masses to simulate the dynamical evolution of the Orion Trapezium, revealing short system lifetimes and the formation of tight binaries or triples.

## Contribution

It provides the first detailed N-body simulations of the Orion Trapezium using observational data, exploring its dynamical evolution and resulting system configurations.

## Key findings

- Dynamical lifetimes are about 10-50 thousand years.
- Most systems evolve into tight binaries or hierarchical triples.
- Properties of evolved systems match some observational characteristics.

## Abstract

We discuss recent observational data on the transverse and radial velocities, as well as on the masses of the main components of the Orion Trapezium. Based on the most reliable values of these quantities we study the dynamical evolution of ensembles of multiple systems mimicking the Orion Trapezium. To this end we conduct numerical $N-$body integrations using the observed masses, planar positions and velocities, radial velocities, and random line-of-sight ($z$) positions for all components. We include perturbations in these quantities compatible with the observational errors. We find the dynamical lifetimes of such systems to be quite short, of the order of 10 to 50 thousand years. The end result of the simulations is usually a tight binary, or sometimes a hierarchical triple. The properties of the evolved systems are studied at different values of the crossing times. The frequency distributions of the major semiaxes and eccentricities of the resulting binaries are discussed and compared with observations.