NGC 6939 | |
---|---|
Observation data (J2000 epoch) | |
Right ascension | 20h 31m 30s[1] |
Declination | +60° 39′ 42″[1] |
Distance | 3,860 ly (1,185 pc[2]) |
Apparent magnitude (V) | 7.8 [1] |
Apparent dimensions (V) | 7' |
Physical characteristics | |
Estimated age | 2.2 billions years[2] |
Other designations | Melotte 231 |
Associations | |
Constellation | Cepheus |
NGC 6939 is an open cluster in the constellation Cepheus. It was discovered by William Herschel in 1798. The cluster lies 2/3° northwest from the spiral galaxy NGC 6946. The cluster lies approximately 4,000 light years away and it is over a billion years old.