NGC 7789  -  Herschel's Spiral Cluster

Full resolution (1600x1200 px  600kB)

Object data of NGC7789

Object type: open cluster (II 2 r)
Size: 16'
Magnitude: 6.7 mag
Constellation: Cas
Distance: 7,600 Ly
Notes: very old cluster (1.5 billion years)

Exposure data

Date: 2007-12-19
Location: Nussbach / Austria (400m)
Telescope: TeleVue NP101 (4" Apo f=540mm)
Camera: ST2000XM with CFW8 and SBIG Filters
  Binning: L 1x1 / RGB 1x1
  Exposure time: L 36x2m / R 8x8m / G 8x4m / B 8x4m
Exposure time total: 3h 20m

bright moon during exposure!