Photometric investigations of distant comets C/2002 VQ94 (LINEAR) and 29P/Schwassmann-Wachmann-1

TL;DR

This study analyzes photometric data of two distant comets, revealing activity beyond water ice sublimation zones, detecting specific emissions indicating formation in cold outer Solar System regions, and identifying active structures in their comas.

Contribution

It provides new insights into the activity and composition of distant comets, including emission spectra and structural features, using observations from a 6m telescope.

Findings

Detection of CO+ and N2+ emissions in comet spectra.

Photometric maximum of the ionosphere shifted relative to dust coma.

Identification of jets in the dust coma of comet 29P/Schwassmann-Wachmann 1.

Abstract

We present an analysis of the results of photometric investigations of two distant comets, C/2002 VQ94 (LINEAR) and 29P/Schwassmann-Wachmann 1, obtained with the 6m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. The comets under study demonstrate sufficient activity out of the zone of water ice sublimation (at heliocentric distances longer than 5 AU). In the spectra of the investigated comets, we found the CO+ and N2+ emission. The presence of this emission may say that the comets were formed in the outer parts of the Solar System, in a protoplanetary cloud at a temperature <=25 K. We found that the photometric maximum of the ionosphere (in the CO+ filter) of the comet C/2002 VQ94 (LINEAR) is shifted relative to the photometric center of the dust coma by 1.4 arcsec (7.44*10^3 km) in the direction deflected by 63 deg from the direction to the Sun. Using special filters to process the images, we picked out active structures (jets) in the dust coma of the 29P/Schwassmann-Wachmann 1 comet.