Optical observations and dust modelling of comet 156P/Russell-LINEAR

TL;DR

This study combines spectroscopic, photometric, polarimetric observations and dust modelling to analyze the dust composition, activity, and jet features of comet 156P/Russell-LINEAR, revealing its typical cometary nature and similarities to comet 67P.

Contribution

It provides a comprehensive multi-method analysis of comet 156P/Russell-LINEAR, including dust composition, activity patterns, and polarization properties, which was not previously documented.

Findings

Presence of strong CN, C3, C2 emissions indicating typical comet composition.

Detection of jets and non-steady state dust outflow.

Dust dominated by large, low-porosity grains with high silicate content.

Abstract

Comet 156P/Russell-LINEAR is a short period Jupiter family comet with an orbital period of 6.44 years. The results from spectroscopic, photometric, polarimetric observations and dust modelling studies are presented here. From the spectroscopic study, strong emissions from $CN (\Delta \nu = 0)$, $C_3 (\lambda 4050$ \AA), $C_2 (\Delta \nu = +1)$ and $C_2 (\Delta \nu = 0)$ can be observed during both the epochs of our observations. The Q($C_2$)/Q(CN) ratio classifies the comet as a typical comet. The imaging data reveals the presence of jets. The dust emission from the comet is observed to have a non-steady state outflow due to the presence of these strong jets which subside in later epochs, resulting in a steady state outflow. Polarimetric study at two different phase angles reveals the degree of polarization to be comparable to Jupiter family comets at similar phase angles. Localized variations in polarization values are observed in the coma. The dust modelling studies suggest the presence of high amount of silicate/low absorbing material and indicate the coma to be dominated by higher amount of large size grains with low porosity having power law size distribution index = 2.4. The observed activity and dust properties points to a similarity to another Jupiter family comet, 67P/Churyumov-Gerasimenko.