Comet 103P / Hartley

2 Oct. 2010

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At left is a cropped, 20-frame stack of Comet 103P/Hartley in Cassiopeia at about magnitude 7.9. This comet was very difficult to locate as it is rapidly moving, with a relatively tight core, and very dim and diffuse symmetrical coma. I ended up verifying its position with a DSLR shot, where the comet's green color made identifying it possible beyond any doubt.
The video sequence here was created with a series of 30-second exposures, one minute apart. Clouds interfered on some frames causing a background color shift.
Both the stacked still and video were created with a Nikon D700 at ISO 3200, on an AP155EDF (f/7) refractor, mounted on a Losmandy Titan mount, operated without active guiding.