The effects of dust outbursts on the anomalistic features observed by Rosetta Alice around 67P/Churyumov-Gerasimenko

摘要

The Alice far-ultraviolet spectrograph on board the Rosetta spacecraft currently operating around the comet 67P/Churyumov-Gerasimenko experiences an anomalistic feature (AF) that has proven nearly constant at comet separations below 450 km. This feature varies rapidly on a time scale of seconds and displays no relation to any measured parameters with the exception of comet separation. Simulations showed that nanograins and ions could create the feature through a range of possible masses, velocities, charges, and energies. This paper builds on research published in Noonan et al. 2016 that explored the behaviors and morphology of the AF. Observations taken on February 19th, 2016 during a dust outburst observed by several other instruments (Eberhard Grun, in prep) verified that the most common morphology of the AF is linked to dust and charged nanograins.