Dynamical evolution and end states of active and inactive Centaurs

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 × 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 (∼ 10 2 − 10 3 yr), while such drops are not found among inactive Centaurs. Inactive Centaurs with T J < ∼ 2.5 usually evolve to Halley-type comets, whereas inactive Centaurs with T J > ∼ 2.5 and active Centaurs (that also have T J > ∼ 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.

Ossos

“…These findings imply that if crystallization is indeed the driver for centaur activity, these centaurs should have suffered from a recent orbital change. This conclusion obtained from thermal evolution modelling seems confirmed by the work by Fernández et al (2018), who studied the dynamical evolution of both active and inactive centaur subpopulations. They showed that while all centaurs may come from the same source region, they have a wide range of dynamical histories, and do not contribute to the same comet populations.…”

From Centaurs to comets: 40 Years

“…Some Centaurs may even become temporarily captured as Trojans of the giant planets for up to 100 kyr (Horner & Evans 2006). Most interesting is the recent finding that active Centaurs tend to evolve to JFCs while the inactive ones tend to evolve to Halley-type comets (Fernández et al 2018).…”

“…As suggested in Jewitt (2009), the identified active Centaurs tend to have lower perihelion (see Figure 1), though notable exceptions, like Chiron, exist. In fact, Fernández et al (2018) found that active and inactive Centaurs have experienced different dynamical evolutions. They suggest that inactive Centaurs deactivated because of a larger permanence far from the Sun while a recent drastic drop in perihelion distance could be responsible of renew the activity in the active ones.…”

Orbital stability in the Solar system for arbitrary inclinations and eccentricities: planetary perturbations versus resonances

“…Then, our maps suggest that the population of objects with 10 < a < 30 is mostly the result of the dynamics imposed by the strongest planetary perturbations. This is not an extraordinary result because we are dealing mainly with Centaurs for which it is well known they are mostly evolving encountering the giant planets (Horner et al 2004;Di Sisto & Brunini 2007;Bailey & Malhotra 2009;Fernandez et al 2018). Fernandez et al (2018), studying the dynamical differences between active and inactive Centaurs, they found that inactive Centaurs have greater dynamical lifetimes than active ones.…”

“…In recent articles it was clearly established that the capture in high inclination mean motion resonances (MMRs) is a common phenomena even for retrograde orbits (Morais & Namouni 2013;Namouni & Morais 2015;Fernández et al 2016;Wiegert et al 2017;Fernandez et al 2018). One decisive factor for the occurrence of these captures is the relatively large strength that some resonances have for the full interval of orbital inclinations (Gallardo 2019).…”