Distant Jupiter family Comet P/2011 P1 (McNaught)

TL;DR

This study analyzed the spectra and images of Jupiter family comet P/2011 P1, finding no detectable gas emissions, measuring its color indices, and modeling its dust coma, providing insights into its composition and dust environment.

Contribution

First spectroscopic and photometric analysis of P/2011 P1, including gas production limits, color measurements, and dust coma modeling.

Findings

No C2 or CO+ emissions detected above 3 sigma.

Measured redder color indices for nucleus and dust.

Modeled dust coma as a spiral galaxy edge.

Abstract

The spectra and images obtained through broadband BVR filters for Jupiter famaly comet P/2011 P1 were analyzed. We observed the comet on November 24, 2011, when its heliocentric distance was 5.43 AU. Two dimensional long slit spectra and photometric images were obtained using the focal reducer SCORPIO attached to the prime focus of the 6-m telescope BTA (SAO RAS, Russia). The spectra cover the wavelength range of 4200-7000 {\AA}. No emissions of C2 and CO+, which are expected in this wavelength region, were detected above 3 sigma level. An upper limit in gas production rate of C2 is expected to be 1.1*10^24 mol*s^-1. The continuum shows a reddening effect with the normalized gradient of reflectivity along dispersion of 5.1% per 1000 {\AA}. The color indices (B-V)=0.89 and (V-R) = 0.42 for the nucleus region or (B-V)=0.68 and (V-R)=0.39 for the coma region, which are derived from the photometric data, also evidence that the color of the cometary nucleus and dust are redder with respect to the Sun. The dust coma like a spiral galaxy adge on was fitted using a Monte Carlo model.