A Kinematic History of Stellar Encounters with Beta Pictoris

Fuente: arXiv
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Autores principales: Gragera-Más, Jose Luis, Torres, Santiago, Mustill, Alexander James, Villaver, Eva
Formato: Preprint
Publicado: 2025
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author Gragera-Más, Jose Luis
Torres, Santiago
Mustill, Alexander James
Villaver, Eva
author_facet Gragera-Más, Jose Luis
Torres, Santiago
Mustill, Alexander James
Villaver, Eva
contents Beta Pictoris is an A-type star hosting a complex planetary system with two massive gas giants and a prominent debris disk. Variable absorption lines in its stellar spectrum have been interpreted as signatures of exocomets (comet-like bodies transiting the star). Stellar flybys can gravitationally perturb objects in the outer comet reservoir, altering their orbits and potentially injecting them into the inner system, thereby triggering exocomet showers. We aim to assess the contribution of stellar flybys to the observed exocomet activity by reconstructing the stellar encounter history of beta Pictoris in the past and future. We used Gaia DR3 data, supplemented with radial velocities from complementary spectroscopic surveys, to compile a catalogue of stars currently within 80 pc of beta Pictoris. Their orbits were integrated backward and forward in time in an axisymmetric Galactic potential (Gala package) to identify encounters within 2 pc of the system. We identified 99 416 stars within 80 pc of beta Pictoris at present with resolved kinematics. Among these, 49 stars (including the eight components of five binaries) encounter beta Pictoris within 2 pc between -1.5 Myr and +2 Myr. For four of the binaries, the centre-of-mass trajectories also pass within 2 pc. We estimate the sample to be more than 60 % complete within 0.5 Myr of the present. Despite beta Pictoris being the eponym of its famous moving group, none of the identified encounters involved its moving group members; all are unrelated field stars. We find no encounter capable of shaping observed disc structures, although stellar flybys may contribute to the long-term evolution of a potential Oort Cloud. Our catalogue constitutes the most complete reconstruction of the beta Pictoris encounter history to date and provides a robust foundation for future dynamical simulations.
format Preprint
id arxiv_https___arxiv_org_abs_2510_02509
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A Kinematic History of Stellar Encounters with Beta Pictoris
Gragera-Más, Jose Luis
Torres, Santiago
Mustill, Alexander James
Villaver, Eva
Solar and Stellar Astrophysics
Earth and Planetary Astrophysics
Astrophysics of Galaxies
Beta Pictoris is an A-type star hosting a complex planetary system with two massive gas giants and a prominent debris disk. Variable absorption lines in its stellar spectrum have been interpreted as signatures of exocomets (comet-like bodies transiting the star). Stellar flybys can gravitationally perturb objects in the outer comet reservoir, altering their orbits and potentially injecting them into the inner system, thereby triggering exocomet showers. We aim to assess the contribution of stellar flybys to the observed exocomet activity by reconstructing the stellar encounter history of beta Pictoris in the past and future. We used Gaia DR3 data, supplemented with radial velocities from complementary spectroscopic surveys, to compile a catalogue of stars currently within 80 pc of beta Pictoris. Their orbits were integrated backward and forward in time in an axisymmetric Galactic potential (Gala package) to identify encounters within 2 pc of the system. We identified 99 416 stars within 80 pc of beta Pictoris at present with resolved kinematics. Among these, 49 stars (including the eight components of five binaries) encounter beta Pictoris within 2 pc between -1.5 Myr and +2 Myr. For four of the binaries, the centre-of-mass trajectories also pass within 2 pc. We estimate the sample to be more than 60 % complete within 0.5 Myr of the present. Despite beta Pictoris being the eponym of its famous moving group, none of the identified encounters involved its moving group members; all are unrelated field stars. We find no encounter capable of shaping observed disc structures, although stellar flybys may contribute to the long-term evolution of a potential Oort Cloud. Our catalogue constitutes the most complete reconstruction of the beta Pictoris encounter history to date and provides a robust foundation for future dynamical simulations.
title A Kinematic History of Stellar Encounters with Beta Pictoris
topic Solar and Stellar Astrophysics
Earth and Planetary Astrophysics
Astrophysics of Galaxies
url https://arxiv.org/abs/2510.02509