Go / no go for deep skyGo / no go for deep sky imaging
M78
reflection nebula in Orion
M78 is the brightest reflection nebula in the sky, a blue cloud of dust lit by two young stars in Orion. Dark lanes cut through it, and nearby fainter nebulae such as NGC 2071 sit in the same field. It lies a few degrees from the Flame Nebula and the Horsehead.
Save your telescope or lens on the planner to lay your camera frame over this diagram.
// Key facts
- Catalog
- M78
- Type
- reflection nebula
- Constellation
- Orion
- Size
- 8′ across
- Brightness
- Magnitude 8.3
- Distance
- about 1,600 light-years
- Peak month (any location)
- Dec
- Typical prime months
- Oct to Mar
- Difficulty
- Intermediate
- Filter
- No filter (broadband); a UV/IR-cut or L filter is enough
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 M78
- No narrowband filter: reflection nebulae are broadband targets, with a clean luminance or UV/IR-cut filter.
- A frame of about 1.5 degrees (700 mm on APS-C) shows M78 with NGC 2071.
- A wide field of 3 to 4 degrees can take in M78 and the Flame Nebula together.
Framing: what focal length?
M78 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 10% |
| 2,000 mm | about 20% |
| 3,000 mm | about 30% |
How high does it climb from your latitude?
The highest point M78 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) | 35° | Workable |
| 45°N (Minneapolis, Milan) | 45° | Workable |
| 35°N (Los Angeles, Tokyo) | 55° | Workable |
| 25°N (Miami, Cairo) | 65° | High in the sky |
| 35°S (Sydney, Santiago) | 55° | 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