Discovered by Caroline Herschel in 1783, this faint cluster in Cassiopeia is easily overlooked.

NGC 7789 – September 14, 2007
Location: DAO, old 16” site.
Constellation: Cassiopeia
Optics: Borg 77EDII at f/4.3
Camera: Canon 20Da on Kenko SkyMemo.
Exposures: 56 light frames of 60 sec, ISO 800.
Process: Calibrated with 30 dark frames and 25 flat frames in ImagesPlus. Combined using MinMax Excluded. Colour balance in Photoshop.