This is NGC 457, the ET or Owl Cluster in Cassiopeia. The small cluster NGC 436 lies above the Owl. A faint planetary nebula, Simeis 22, is to the left, but is barely recorded here in these short unfiltered exposures. The field contains quite a few yellow giant stars. This is a stack of 12 x 3-minute exposures, stacked to average out the many satellite trails that appeared on the sub-frames. This was with the Starfield Géar90 apo refractor at f/4.8 with its Reducer/Flattener, and Canon Ra at ISO 1600. Autoguided and dithered with the Lacerta MGEN3 autoguider.
Messier and NGC clusters in eastern Cassiopeia, taken Sept. 14, 2007 for stack of 4 x 4 minute exposures with 135mm L-series lens at f/2.8 and Canon 20Da camera at ISO 800. Simulates binocular field. Includes M103, NGC 663, NGC 654; NGC 659; NGC 457. Faint spot at upper left is cluster IC 166.
The large open cluster NGC 752 in Andromeda, taken Sept. 14, 2007 for stack of 4 x 3 minute exposures with 135mm L-series lens at f/2.8 and Canon 20Da camera at ISO 800. Simulates binocular field.
