Comet C/2017 K2 (PANSTARRS): dynamically old or new?

TL;DR

This study uses N-body simulations to determine whether comet C/2017 K2 is a dynamically old Oort cloud object or a dynamically new interstellar visitor, concluding it is likely the former.

Contribution

The paper provides a detailed dynamical analysis using simulations to classify C/2017 K2's origin, challenging previous assumptions of its interstellar nature.

Findings

67% of simulated orbits are consistent with a bound, old Oort cloud origin.

29% of orbits suggest an interstellar origin.

The comet is likely not dynamically new from the Oort cloud.

Abstract

At discovery time, C/2017 K2 (PANSTARRS) was the second most distant inbound active comet ever observed. It has been argued that this object is in the process of crossing the inner Solar System for the first time, but other authors have concluded that it is dynamically old. We have performed full N-body simulations for 3 Myr into the past using the latest public orbit determination for this object and most of them, 67%, are consistent with a bound and dynamically old Oort cloud comet, but about 29% of the studied orbits are compatible with an interstellar origin. Our independent calculations strongly suggest that C/2017 K2 is not a dynamically new Oort cloud comet.