Open cluster · Cepheus
NGC 6939 Ghost Bush Cluster
mag 7.812′ across
About
NGC 6939, the Ghost Bush Cluster, is an open cluster of magnitude 7.8 in Cepheus, about 12′ across.
How to find it
- NGC 6939 is in the constellation Cepheus.
- Best evenings: around mid-September it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
- Where on Earth: it is seen well, at least 10° up, from north of 19° S.
When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.
What you will see
- EyesNot visible to the naked eye.
- Binoculars (10×50)A faint, grainy patch.
- Telescope (6–8 inch)A group of faint stars.
For a dark country sky with no Moon. From a city, faint galaxies and nebulae can disappear completely.
Facts
| Designations | NGC 6939 |
|---|---|
| Type | Open cluster |
| Magnitude | 7.8The smaller the number, the brighter. |
| Apparent size | 12′the full Moon is 31′ across |
| Constellation | Cepheus |
| Right ascension (J2000) | 20h 31m 30.1s |
| Declination (J2000) | +60° 39′ 44″ |
Sources and credits
Catalog data: OpenNGC by Mattia Verga, CC BY-SA 4.0, and d3-celestial by Olaf Frohn, BSD 3-Clause. All data sources →