I captured this image of Comet Lulin just prior to the beginning of twilight.

C/2007 N3 Lulin – January 29, 2009
Constellation: Libra
Location: Mojave National Preserve, CA
Optics: Borg 77EDII at f/4.3 on HEQ5 mount
Camera: Canon 20Da
Exposures: 8 light frames of 60 sec, ISO 800.
Process: Calibrated with 20 dark frames and 20 flat frames in ImagesPlus. Combined using MinMax Excluded. Colour balance adjustment and cropped in Photoshop.