Object: Open cluster DO 13 Constell: CAS RA: 00h 50.0m Decl: +64° 08' Epoch: 2000 Mag: 8m (own) Size: 12' Type: III 1 p Observer: Jere Kahanpää Obs. place: Hartola, Finland Date/Time: 24./25.8.1996, 00.27 Telescope: N 205/1000 Magn: 80x Filter: Field: 37' NE Lim.mag: 5.8m Background sky: 3-4 Seeing: 2 Weather: +9 °C, 2/3 low SW. Brightness: 2 Alt: 65° Description: A easy cluster. The Trumpler class fits well: Detached but not concentrated. Diameter 14'. About 30 stars mag. 11...12, most being 11m. 15' SW from a 6th magnitude star. Irregular.