Go / no go for deep skyGo / no go for deep sky imaging
NGC 6820
emission nebula in Vulpecula
NGC 6820 is a faint emission nebula in Vulpecula, together with the open cluster NGC 6823 beside it. It is a modest target, but it sits in a rich Milky Way field in the summer sky, a short distance from the Dumbbell Nebula.
Save your telescope or lens on the planner to lay your camera frame over this diagram.
// Key facts
- Catalog
- NGC 6820
- Type
- emission nebula
- Constellation
- Vulpecula
- Size
- 12′ across
- Brightness
- Magnitude 7.1
- Distance
- around 6,000 light-years
- Peak month (any location)
- Jul
- Typical prime months
- May to Sep
- Difficulty
- Advanced
- Filter
- Narrowband: Ha / OIII / SII, or a dual-band / UHC filter
Pick a saved location or share your device location. Your coordinates are used only to calculate tonight and are not stored. To save locations, use the planner.
How to image NGC 6820
- Ha or dual-band is needed to bring out the faint nebulosity.
- A frame of about 1 degree (around 1,000 mm on APS-C) shows the nebula and the cluster.
- High in the sky on summer evenings from northern sites.
Framing: what focal length?
NGC 6820 is small, so a "60% of the frame" focal length would be impractical. Here is how much of an APS-C frame it covers at common long focal lengths; expect to crop.
| Focal length | Share of the frame width |
|---|---|
| 1,000 mm | about 15% |
| 2,000 mm | about 30% |
| 3,000 mm | about 45% |
How high does it climb from your latitude?
The highest point NGC 6820 reaches in the sky. Above about 60° is excellent, 30° to 60° is workable, and under 30° you are looking through a lot of air.
| Latitude | Highest point | Rating |
|---|---|---|
| 55°N (Scotland, Alaska) | 58° | Workable |
| 45°N (Minneapolis, Milan) | 68° | High in the sky |
| 35°N (Los Angeles, Tokyo) | 78° | High in the sky |
| 25°N (Miami, Cairo) | 88° | High in the sky |
| 35°S (Sydney, Santiago) | 32° | Workable |
Also worth imaging
Want a GO / NO-GO verdict for tonight, with clouds, moon, seeing and a full dark-window timeline?
Open the planner