Object: Open cluster NGC 7789 Constell: CAS RA: 23h 57.0m Decl: +56° 44' Epoch: 2000 Mag: 6.7m Size: 16' Type: II 1 r Observer: Jere Kahanpää Obs. place: Hartola, Finland Date/Time: 31./1. 8./9. 1997, 00.20-00.55 Telescope: N 205/1000 Magn: 80x Filter: - Field: 37' NE Lim.mag: 6.2m Background sky: 2 Seeing: 3 Weather: +14 °C, no Moon. Brightness: 3 Alt: 70° Description: An showpiece, easy with 9x25 binoculars. Hundreds of stars resolved at 80x. A system of dark lanes seems to cut the cluster into several separate condensations. The brightest such patch lies in the S part of the cluster and is surrounded by a sharply defined oval dark ring with a diameter of 3'. Another somewhat more diffuse ring lies N of the first. Diam. of the whole system is about 12'.