The Odd Comet 157P/Tritton and Its Misunderstood Fragmentation

TL;DR

This paper investigates the complex fragmentation and activity history of comet 157P/Tritton, revealing multiple companions and clarifying misconceptions about its observed fragments through detailed orbital analysis.

Contribution

It provides new fragmentation solutions for the comet's companions, correcting previous misunderstandings and offering insights into its unusual activity and fragmentation events.

Findings

Comet 157P experienced multiple fragmentation events.

Two distinct companions were identified with specific orbital residuals.

The 2017 outburst was linked to nuclear fragmentation.

Abstract

Comet 157P is a faint object with a history of being prone to unfortunate situations, circumstances, and/or coincidences. Several weeks after its 1978 discovery the comet disappeared and remained lost nonstop for twenty five years. Rediscovered in 2003 as a new comet, it was about 500 times brighter than in 1978, caught apparently in one of its outbursts. The comet was not detected 200 days after its 2016 perihelion, being fainter than mag 20, but 80 days later it was mag 16 and gradually fading back to mag 20 over a period of four months. The comet did not miss the opportunity to have a close encounter with Jupiter, having approached it to less than 0.3 AU on 2020 February 10. The 2017 outburst or surge of activity appears to have accompanied an event of nuclear fragmentation. The birth of a second companion is dated to the months following the Jupiter encounter. The series of weird episodes culminated near the 2022 perihelion, when one companion brightened to become observable for two weeks and after another two weeks the other flared up to be seen for the next two weeks. Unnoticed, this incredible coincidence fooled some experts into believing that a single object, designated 157P-B, was involved, even though its orbit left large residuals. I now offer representative fragmentation solutions for the two companions, the mean residuals amounting to +/-0".4 and +/-1".0, respectively.