Object: Open cluster NGC 6633 Constell: OPH RA: 18h 27.7m Decl: +06° 34' Epoch: 2000 Mag: 4.6m Size: 27' Type: III 2 m Observer: Jere Kahanpää Obs. place: Helsinki, Finland Date/Time: 16./17.9.1996, 23.00 Telescope: R 135/1950 Magn: 40x (?) Filter: Field: 80' NE Lim.mag: 5.4m Background sky: 3-4 Seeing: 3 Weather: +5 °C, no Moon. Brightness: 1 Alt: 25° Description: A beautiful cluster in a very rich field. About 15 very bright (8-9m) stars and 20 fainter ones. Diameter about 30', clearly elongated W-E, N-S diameter 15'.