Study of a Potential Relationship Between Two Long-Period Comets and Rapid Inward Drifting of Aphelion Due to Orbital-Cascade Resonance

TL;DR

This study investigates the potential genetic link between two long-period comets, revealing that orbital evolution and cascade resonance with Jupiter could explain rapid inward drifting of their aphelia, challenging prior assumptions of their common origin.

Contribution

The paper introduces the concept of orbital-cascade resonance as a mechanism for rapid inward drifting of comet aphelia, providing new insights into long-period comet orbital evolution.

Findings

C/1846 O1 has a ~500-year period, much shorter than C/1973 D1.

Orbital integration suggests possible past encounters with Jupiter affecting their orbits.

Orbital-cascade resonance can cause rapid inward drifting of comet aphelia.

Abstract

We study a potential genetic relationship of comets C/1846 O1 and C/1973 D1, whose apparent orbital similarity was tested by Kresak (1982) only statistically, using the Southworth-Hawkins (1963) criterion D. Our orbit determination for C/1846 O1 shows its period was ~500 yr, ~30 times shorter than that of C/1973 D1. Formerly unrecognized, this incongruity makes the objects' common origin less likely. Long-term orbit integration suggests that, if related, the two comets would have to have separated far away from the Sun (probably ~700 AU) 21 millennia ago and, unlike C/1973 D1, C/1846 O1 would have to have been subjected to a complex orbital evolution. Given the chance of encountering Jupiter to ~0.6 AU some 400 days after perihelion, C/1846 O1 and C/1973 D1 may have been perturbed, during their return in the 15th millennium BCE, into orbits that were, respectively, smaller and larger than was the parent's, with a net difference of more than 0.002 (AU)^{-1} in 1/a. Whereas C/1973 D1 was on the way to its 1973 perihelion, C/1846 O1 should have been subjected to recurring encounters with Jupiter, during which the orbital period continued to shorten by integral multiples of the Jovian orbital period, a process called high-order orbital-cascade resonance. While the integrated perturbation effect of C/1846 O1 by Jupiter does not appear to reduce the comet's orbital period to below ~1200 yr by the mid-19th century, we find that orbital-cascade resonance offers an attractive mechanism for rapid inward drifting of aphelion especially among dynamically new comets.