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Subject
Comet Machholz
Date
2nd January 2005
Telescope or Lens
Tak FS60C with AP 0.75 focal reducer
Mount
G11
Camera
ST2000XM
Filters
TT LRGB and Hutech LPR
Total Exposures L 15 min R 15 min G 15 min B 15 min
Sub exposure
10 x 90 sec
10 x 90 sec
10 x 90 sec
10 x 90 sec
Binning
Luminance 1 x 1 RGB 1 x 1
Field of view and resolution
Approx 160 x 122 Arcminute. 6 Arcsec / Pixel
Comments  
Time approx 23:00 UT. Unguided exposures after training the mount to follow the comet.

This is my first RGB image of a comet. I am not that pleased with it and I think I made several mistakes.

1. Using the Hutech LPR filter cut down the signal.

2. The wide field of view coupled with a large number of exposures led to star trails that crossed each other, even though enough time was left between exposures to produce "dotted" trails, this led to artifacts in the SD mask combined images.

3. the low signal in the tail meant that the stretch required to show it also showed the artifacts from the star trails.

I will try again without the LPR filter and use an IR blocker instead. Hopefully this will allow shorter exposures or get a better signal.

An image taken through the blue filter only on 1st January 2005 can be found here.