A dynamical analysis of the Taurid Complex: evidence for past orbital convergences

TL;DR

This study investigates whether the Taurid Complex's current orbital similarities result from a common fragmentation event or from dynamical processes, using backward numerical simulations of orbital convergence over 20,000 years.

Contribution

It provides evidence for past orbital convergences among TC objects, suggesting a possible fragmentation origin around 3200 BCE, while considering alternative dynamical explanations.

Findings

Twelve pairs of bodies showed past orbital convergence within 20,000 years.

Convergence suggests a fragmentation event 5-6 thousand years ago.

Dynamical processes could also explain orbital similarities without a common origin.

Abstract

The goal of this work is to determine if the dynamics of individual Taurid Complex (TC) objects are consistent with the formation of the complex via fragmentation of a larger body, or if the current orbital affinities between the TC members result from other dynamical processes. To this end, the orbital similarity through time of comet 2P/Encke, fifty-one Near-Earth Asteroids (NEAs) and sixteen Taurid fireballs was explored. Clones of each body were numerically simulated backwards in time, and epochs when significant fractions of the clones of any two bodies approached each other with both a low Minimum Orbit Intersection Distance and small relative velocity were identified. Only twelve pairs of bodies in our sample show such an association in the past 20 000 years, primarily circa 3200 BCE. These include 2P/Encke and NEAs 2004 TG10, 2005 TF50, 2005 UR, 2015 TX24, and several Southern Taurid fireballs. We find this orbital convergence to be compatible with the fragmentation of a large parent body five to six thousand years ago, resulting in the separation of 2P/Encke and several NEAs associated with the TC, as well as some larger meteoroids now recorded in the Taurid stream. However, the influence of purely dynamical processes may offer an alternative explanation for this orbital rapprochement without requiring a common origin between these objects. In order to discriminate between these two hypotheses, future spectral surveys of the TC asteroids are required.