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Comet 17P/Holmes on 2007-11-11, photographed with an
f = 400 mm f/6.3 lens. This is a stack of four frames
of 2 min exposure each, the field is about 1.5°. A stack of
dark frames and a bilinear sky background have been subtracted,
removing the sodium glare of the city. (Photograph by Horst
Meyerdierks.)
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