46p wirtanen

Forecast was for clear skies last night but stepping outside around 9pm there was a thin layer of cloud/fog overspreading the sky.  It was still possible to see the brighter stars and the moon, but transparency was highly compromised.  I was disappointed because I wanted to observe comet 46p Wirtanen, now at magnitude 5, and it was forecast to be cloudy for the next week at least.

I hesitated to roll off the shed and set-up Big Blue.  I started to head inside, but decided to try to find the comet with my 7x35 binoculars -- and after a while I thought I could make out a small round glow where the comet was to be.  So I thought, what the hell, give it a shot.

Soon enough I swept up the comet in my 80mm finder, still the faint glow but now with a quasi-stellar nucleus, then settled in to view at 101x in the scope.  The comet was in line with the base of three stars which formed an equilateral triangle.  This would make it easy to track movement.  My tracking platform was nearly dead on, with a very slow drift to the west after 20 minutes.  In the scope the halo was round and very diffuse.  With the comet filter the psudo-nucleus was muted and the halo was less round; in fact it was pushed to the NW to form the beginnings of a fat tail.

I tracked the movement of the comet over the next 40 minutes.  I made sketches every 10 minutes and the movement was obvious; the triangle stretched into a diamond with the comet as the fourth "star."  In between I watched the just-past quarter moon set, lit side down like a fishing float, glowing yellow in a haze of cloud.  After making an observation of the comet I was startled to see the moon set behind the ridge of a neighbor's house.

Always very cool to observe a comet moving.  I'm glad I stayed out for it.