Comet Garradd (C/2009 P1)


On the last night of the 2011 Oregon Star Party this recent comet seemed to be the thing to shoot. The QSI camera is monochrome with a color filter wheel and since the comet is moving it’s not really possible to do sequential color. So this is really a monochrome image that I hand colored to show what the comet actually looks like. Of course, there is also special processing to make the comet appear stationary: The sub-exposures were stacked twice; once for the comet and again for stars. The comet was then “clipped” from its frame, cleaned up to get rid of remaining star trails, and pasted over the background image.

 Scope: AT111EDT at f/5.6
Mount: CGEM
Camera: QSI 583 at –15C
Exposure: 10 x 120s L, (20 mins total)


About Greg Marshall

I am a retired electronics engineer and after a few months of enjoying my leisure I began to miss doing product development. My astronomy hobby always needed new solutions to unique problems, so I decided that whenever I came up with a good solution I would try to make it available to others.

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