Comet Holmes, 17P, taken Nov 1, 2007 on excellent night.
Comet Holmes, 17P, taken Nov 1, 2007 on excellent night. Taken with A&M 105mm apo refractor at f/5 with Borg compressor/field flattener on SkyWatcher HEQ5 mount. Canon 20Da camera at ISO400. Composite of 4 min, 2min, 1min, 30sec, 15sec, and 7 sec exposures, each exposure being a stack of 3 to 4 identical exposures. Registered and stacked in Photoshop (HDR mode did not produce usable result, so manually composited with sucessively smaller masks to reveal short exposure content around nucleus. Contrast exaggerated with Curves to bring out very faint tail structure. North up, so tail to the S and is dot at upper left of inner coma, other star in inner coma at right is a field star
Size: 5400px × 3603px
Photo credit: © Alan Dyer / VWPics / Alamy / Afripics
License: Licensed
Model Released: No
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