Dynamical evolution and end states of active and inactive Centaurs

TL;DR

This study uses numerical simulations to compare the dynamical evolution, end states, and transfer pathways of active and inactive Centaurs, revealing differences in lifetimes, orbital changes, and cometary outcomes.

Contribution

It provides new insights into how activity correlates with dynamical lifetime and end states, highlighting the role of orbital parameters and recent perihelion drops.

Findings

Inactive Centaurs have about twice the median lifetime of active ones.

High-inclination and retrograde Centaurs are all inactive and have the longest lifetimes.

Inactive Centaurs with low Tisserand parameter often evolve into Halley-type comets.

Abstract

We numerically study the dynamical evolution of observed samples of active and inactive Centaurs and clones that reach the Jupiter-Saturn region. Our aim is to compare the evolution between active and inactive Centaurs, their end states and their transfer to Jupiter family comets and Halley-type comets. We find that the median lifetime of inactive Centaurs is about twice longer than that for active Centaurs, suggesting that activity is related to the residence time in the region. This view is strengthened by the observation that high-inclination and retrograde Centaurs (Tisserand parameters with respect to Jupiter $T_J < 2$) which have the longest median dynamical lifetime ($=1.37 \times 10^6$ yr) are all inactive. We also find that the perihelion distances of some active, comet-like Centaurs have experienced drastic drops of a few au in the recent past ($\sim 10^2-10^3$ yr), while such drops are not found among inactive Centaurs. Inactive Centaurs with $T_J \lsim 2.5$ usually evolve to Halley-type comets, whereas inactive Centaurs with $T_J \gsim 2.5$ and active Centaurs (that also have $T_J \gsim 2.5$) evolve almost always to Jupiter family comets and very seldom to Halley type comets. Inactive Centaurs are also more prone to end up as sungrazers, and both inactive and active Centaurs transit through different mean motion resonances (generally with Jupiter) during their evolution.