Object: Open cluster DO 12 Constell: CAS RA: 00h 40.8m Decl: +60° 51' Epoch: 2000 Mag: Size: 18' Type: IV 2 p (own) Observer: Jere Kahanpää Obs. place: Helsinki, Finland Date/Time: 10./11.10.1996, 21.55 Telescope: C 200/2000 Magn: 160x Filter: Field: 19' NE Lim.mag: 5.4m Background sky: 4 Seeing: 2-3 Weather: +5 °C, no Moon. Brightness: 3 Alt: 70° Description: The cluster should fill the field. and should be centered on the brightest star of the northern group. The northern group (in the middle of the field): About 15 stars with a large range of magnitudes. Scattered but clearly detached. Stars mag. 10... Diam. 7'. The southern group (near the SW edge of the field): A bit fainter than the main group. Most stars mag 12 and a few fainter ones. Triangular outline. A dozen stars within 6'. I think Do 12 includes (and is) these two groups which are probably asterisms. Quite a nice field though.