# A search of reactivated comets

## TL;DR

This study searches archival images to identify reactivated short-period comets, finding two candidates and estimating a low reactivation rate, suggesting most comets are dormant only briefly and that future surveys could discover more such events.

## Contribution

It provides the first systematic search for reactivated comets and estimates their reactivation rate, highlighting the transient nature of comet dormancy.

## Key findings

- Identified two reactivated comet candidates.
- Estimated reactivation rate of approximately 0.007 per orbit.
- Most short-period comets are dormant for less than a few orbits.

## Abstract

Dormant or near-dormant short-period comets can unexpectedly regain ability to eject dust. In many known cases, the resurrection is short-lived and lasts less than one orbit. However, it is possible that some resurrected comets can remain active in latter perihelion passages. We search the archival images of various facilities to look for these "reactivated" comets. We identify two candidates, 297P/Beshore and 332P/Ikeya-Murakami, both of which were found to be inactive or weakly active in the previous orbit before their discovery. We derive a reactivation rate of $\sim0.007~\mathrm{comet}^{-1}~\mathrm{orbit}^{-1}$, which implies that typical short-period comets only become temporary dormant for less than a few times. Smaller comets are prone to rotational instability and may undergo temporary dormancy more frequently. Next generation high-cadence surveys may find more reactivation events of these comets.