Photometric and spectroscopic analysis of Comet 29P/Schwassmann-Wachmann 1 activity

TL;DR

This study presents photometric and spectroscopic observations of comet 29P/Schwassmann-Wachmann 1, revealing its composition, activity level, and coma morphology, including jets, at a distance of 5.25 AU from the Sun.

Contribution

First detailed spectroscopic detection of CO+ and N2+ emissions in this comet at large heliocentric distance, with comprehensive analysis of its activity and coma features.

Findings

Detection of CO+ and N2+ emissions in the coma.

Measured high activity indicator Afρ = 2584 cm.

Identified two jets in the coma morphology.

Abstract

We carried out photometric and spectroscopic observations of comet 29P/Schwassmann-Wachmann 1 at the 6-m BTA telescope (SAO RAS, Russia) and the 1.6-m telescope of the National Laboratory for Astro-physics (LNA, Brazil) on February 20, 2012, and on May 31, 2011, respectively. The spectra revealed the presence of CO+ and N2+ emissions in the cometary coma at a distance of 5.25 AU from the Sun. The ratio [N2+]/[CO+] within the projected slit is 0.013. The images obtained through BVR filters showed a bright, dust coma, indicating a high level of activity. We estimated a colour index and a colour excess for the comet. The parameter Af\r{ho}, which is used as an indicator of a cometary activity, was measured to be 2584 cm in the reference optical aperture of \r{ho}=10^4 km. The dust production constituted 33 kg/s and 9.3*10^3 kg/s, it was obtained using different methods. We also investigated the morphology of the comet using image enhancement techniques and found two jets in the coma.