M39 (NGC 7092) Cyg open cluster
Difficulty level 1

Date of observation: 2000/08/28 02:19
Observing site: Hoshinomura
Transparency/seeing/sky darkness: 3/4/2
Instruments: 32cm Dobsonian with WF32 at 50x
Width of field: 1.4�‹
This is an open star cluster northeast of Deneb. It is bright and large. Individual stars are bright, but there are not many stars contained in the cluster nor much concentration. Perhaps because of this it is not a popular telescopic object. However, if you look at arrangements of the stars in the cluster, you will notice a beautiful equilateral triangle with a double star in the center. The cluster is formed mainly of bright stars with few faint stars. Even in a 3cm finderscope several stars are resolved and the cluster shows a triangular shape.

There are many faint stars north of the cluster appearing as an extended nebulosity, but they are not part of this cluster.