Hardware
& Software: HP S20xi film scanner & Hamrick Vuescan 7.1.1. The
scan was processed, and cropped, using Picture
Window 3.0. Info:
Comet Linear C/2000 WM1 was photographed on
November 21, 2001, The slow photographic speed of
the ETX proved to be a challange for this shot.
I'm also sure that the 4.5 mag skies this shot
was taken from played a roll. You may notice that
the stars are trailed in the image, this is
because the autoguider was tracking the comet and
it is quickly moving relative to the background
stars. I used the 10" as my guide scope for
the ST-4. Even with the 10" the ST-4 needed
a 6 second exposure with the gain set to 3x in
ccdtrack in order to track on the comet.
Interestingly, at one point during a different
exposure, a star entered the ST-4's guide box.
When the star left the guide box, ccdtrack kept
right on guiding on the comet. This resulted in
ccdtrack averaging the positions of the star and
the comet and all the star trails show a kink at
that point.
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