TRAPPIST photometry and imaging monitoring of comet C/2013 R1(Lovejoy): Implications for the origin of daughter species

TL;DR

This study uses TRAPPIST telescope data to analyze the gas and dust activity of comet C/2013 R1 (Lovejoy), revealing asymmetrical production rates, active zones, and potential sources of daughter species, enhancing understanding of comet composition.

Contribution

It provides detailed monitoring of multiple species and dust, identifying different origins of daughter species and their relation to comet activity, which is a novel comprehensive analysis.

Findings

Gas and dust jets indicate active zones on the nucleus.

C2 and C3 likely released from organic and icy grains.

HCN is the main parent molecule for CN.

Abstract

We report the results of the narrow band photometry and imaging monitoring of comet C/2013 R1 (Lovejoy) with the robotic telescope TRAPPIST (La Silla observatory). We gathered around 400 images over 8 months pre- and post-perihelion between September 12, 2013 and July 6, 2014. We followed the evolution of the OH, NH, CN, C3 , and C2 production rates computed with the Haser model as well as the evolution of the dust production. All five gas species display an asymmetry about perihelion, the rate of brightening being steeper than the rate of fading. The study of the coma morphology reveals gas and dust jets which indicate one or several active zone(s) on the nucleus. The dust, C2 , and C3 morphologies present some similarities while the CN morphology is different. OH and NH are enhanced in the tail direction. The study of the evolution of the comet activity shows that the OH, NH, and C2 production rates evolution with the heliocentric distance is correlated to the dust evolution. The CN and, to a lesser extent, the C3 do not display such a correlation with the dust. These evidences and the comparison with parent species production rates indicate that C2 and C3 on one side and OH and NH on the other side could be -at least partially- released from organic-rich grains and icy grains. On the contrary, all evidences point to HCN being the main parent of CN in this comet.