Choosing A Telescope
Telescope Aperture Considerations
The Bonds: Pioneers of American Astronomy
Refractor Dobsonian Style Mounts
Introduction to Planetary Drawings
Saturn's Encke Minima and Encke Division
2001 and 2002 Leonid Meteor Shower
Nature and Travel Photography
Comet Pojmanski (C/2006 A1), March 8th, 2006
Comet Pojmanski (C/2006 A1), March 8th, 2006, 8:45 - 9:50 UT, seeing 5, transparency 5.3.
TMB Optical 175mm f/8 refractor on its homemade Dobsonian-style mount. Magnification 70x - 88x, field of view approximately 1.1 degrees. West is at the top of this sketch, east to the bottom, north to the left and south to the right.
The comet had a relatively bright pseudonucleus, inner coma and outer coma and appeared light blue-green in color. The outer coma had a gauze-like look to it, and the pseudonucleus, inner coma and outer coma reminded me of a galaxy.
The tail was faint and I used similar techniques as during my last observing session to bring out the finer detail. This included using averted vision, gently tapping the tube assembly, moving the telescope back and forth, and placing the comet outside of the field of view and let it drift back into view.
From these techniques I was able to see the both the gas and dust tail. The gas tail, except for a portion that extended off towards the 11:00 o'clock position, extended almost straight back from the coma towards the west or top of the field of view and appeared striated. I was able to trace the length of the gas tail to around two degrees. A feathery dust tail was visible on the south or right hand side of the coma. There appeared to be an additional thinner dust tail that extended off from the outer coma at a 45-degree angle. It was slightly brighter than the gas tail.
With the unaided eye the comet was visible, and through a pair of Oberwerk 11 x 70mm binoculars I was able to detect the tail.
Observing this comet reminded me of another comet that was visible twenty years ago in the spring of 1986, Comet Halley. Like Comet Pojmanski, Halley was low in the sky, which made it a challenge to observe. This was because when Halley was at its closest and brightest, on April 10th, it was below the horizon from 42.5 degrees north where I lived at the time. So I had to observe it in late March and early April when the comet was only around 10 degrees in elevation before astronomical twilight set in.
Comet Pojmanski may not have been the brightest comet visually I have ever seen. However, observing and sketching comets has always represented somewhat of a personal mile marker for me in my own life: where I lived at the time when I observed the comet, what my family and work life was like then, and the astronomy equipment I owned and used at the time. So from that perspective the all the comets I have been fortunate enough to observe have had a special meaning to them.