Analysing the Onset of Cometary Activity by the Jupiter-Family Comet 2023 RN3

TL;DR

This study documents the first observed cometary activity of Jupiter-family comet C/2023 RN3, using multi-instrument observations over 7 months, revealing sustained activity, a coma, and orbital changes potentially linked to planetary encounters.

Contribution

It provides the first detailed analysis of C/2023 RN3's activity onset, combining observational data and orbital simulations to understand its behavior and possible triggers.

Findings

Detected sustained cometary activity starting August 2023

Observed a spatially-extended coma indicating active dust emission

Orbital analysis suggests recent planetary encounter may influence activity

Abstract

We utilize serendipitous observations from the Asteroid Terrestrial-impact Last Alert System (ATLAS) and the Zwicky Transient Facility (ZTF) in addition to targeted follow-up observations from the Las Cumbres Observatory (LCO) and Liverpool Telescope to analyze the first observed instance of cometary activity by the newly-discovered Jupiter-family comet C/2023 RN3 (ATLAS), whose orbital dynamics place it close to residing on a Centaur-like orbit. Across our 7-month baseline, we observe an epoch of cometary activity commencing in August 2023 with an increase in brightness of >5.4 mag. The lightcurve of 2023 RN3 indicates the presence of continuous cometary activity across our observations, suggesting the onset of a new period of sustained activity. We find no evidence of any outbursts on top of the observed brightening, nor do we find any significant color evolution across our observations. 2023 RN3 is visibly extended in LCO and Liverpool Telescope observations, indicating the presence of a spatially-extended coma. Numerical integration of 2023 RN3's orbit reveals the comet to have recently undergone a slight increase in semimajor axis due to a planetary encounter with Jupiter, however whether this orbital change could trigger 2023 RN3's cometary activity is unclear. Our estimate for the maximum dust production metric of Afrho ~400 cm is consistent with previous measurements for the Jupiter-family comet and Centaur populations.