@misc{9247313,
  abstract     = {{β Pictoris is a nearby, young planetary system hosting an edge-on oriented dust disk. It is not only the system where the first exocomets were discovered, but also the most studied exocomet system. Decades of observations since the first exocomet discovery in the 1980’s have shown spectroscopic transits of evaporating exocomets at close orbital distances to the host star. Although many observational and theoretical studies have been carried out since discovery of the β Pictoris exocomet phenomenon, the physical nature and origins of these exocomets remain poorly understood. The aim of this thesis is to, through N-body simulations and theoretical modeling, relate to exocometary observations, determine likely regions of exocomet origin in the system as well as plausible mechanisms that drive the creation of the exocomets observed in β Pictoris. This work presents a simulation where the β Pictoris system was integrated together with a disk of over 100 thousand test-particles for 25 Myr, longer than the estimated age of the system. The simulation resolves
close encounters between the simulated test-particles and the two planets of the system, as it uses the non-symplectic Rebound integrator IAS15.

The results show that the system is generally highly dynamically unstable on short time-scales. Most of the test-particles initiated below ∼ 35 AU are removed from the simulation, while the system is stable beyond this limit as the planetary perturbations have not yet reached this distance after 25 Myr. The simulation revealed additional regions of stability, one interior to the orbit of β Pictoris c and another region outside of the orbits of the planets, distributed in smaller semi-major axis ranges of stability between 20 and 25 AU.
The results presented in this thesis show that exocomets can be sourced from these two regions of stability, as well as the inner edge of the ∼ 35 AU stability region, at time-scales that are on the order of the age of the system. Exocomets are produced from two main regions of the β Pictoris system, the region interior to the planetary orbits and the region exterior to the orbits of the planets.

This thesis proposes that the two populations of exocomets, sourced from the two identified regions of stability, could correspond to the two families of exocomets observed spectroscopically in β Pictoris. The inner population exocomets are in the simulation created by eccentricity excitation through resonant interactions with β Pictoris c, resulting in a narrow distribution of radial velocities similar to one of the observed exo- comet families. A broad radial velocity distribution is obtained for the exocomets of the outer population
who are driven into the vicinity of the star through disruption by the two planets. This population could correspond to the second observed exocomet family. The outer population exocomets originate from outside of the water sublimation limit of the system and are efficiently transported from this region onto stargrazing orbits. Compositional differences of the exocomets from the two populations are therefore expected. This work predicts that a fraction of the exocomets observed in β Pictoris today could have a significant, unseen,
volatile content. A portion of the results presented here have also been published in Jaworska & Hoeijmakers
(2026).

Additionally to the simulations, modeling of the sublimated exocometary material was performed in this study. This modeling found that the dynamical properties of ions in the gas released by exocomets could explain why certain elements are observed much more commonly than others. In particular, the recently discovered neutral sodium was found to strongly be affected by radiation pressure and have a short ionization time, making it unobservable at short distances to the star, where exocomets are expected. Neutral sodium could become observable on occasions where mechanisms such as fragmentation of the exocometary nucleus and/or exceptionally high electron density are present.}},
  author       = {{Jaworska, Klaudia}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{The Exocomets of β Pictoris: A study of exocometary dynamics}},
  year         = {{2026}},
}