by Rex Parker
A group of AAAP members met at the Observatory Jan 19 to seek comet 2016 R2 with the Mallincam/5″refractor. They succeeded in this challenge – which took some skill as the comet was very faint, TheSkyX reporting magnitude 13.2 as the comet receded away from earth and sun (well past it’s peak brightness). I was not able to attend that observing session but was able to get an image of the comet on the same night locally, using a 12.5″ telescope and CCD camera at home.
The comet picture below is assembled from 6 x 2 min exposures in each color filter (L,R,G,B) taken at intervals over 40 min. By tracking using the comet’s orbital elements rather than sidereal rate tracking, the comet is stationary in the composite image while the field stars trail. Just the faintest hint of a dispersed comet tail might be seen in the image going to the right from the head.
This image gives a different look to the comet compared to the technique used by member Ted Frimet using Skynet, who took shorter images at intervals using Skynet with the mount tracking the stars, revealing the comet’s motion against the steady background stars when displayed as video.