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Lagoon Nebula (M8)
emission nebula in Sagittarius
The Lagoon Nebula is a bright, huge star-forming region in Sagittarius, rich in red glowing gas and bordered by a young cluster of hot stars. It is large enough for a wide-field camera, and it sits next to the Trifid Nebula, so wide frames can catch both.
Save your telescope or lens on the planner to lay your camera frame over this diagram.
// Key facts
- Catalog
- M8
- Type
- emission nebula
- Constellation
- Sagittarius
- Size
- 1.5° across
- Brightness
- Magnitude 6
- Distance
- about 4,000 to 5,000 light-years
- Peak month (any location)
- Jun
- Typical prime months
- Apr to Sep
- Difficulty
- Beginner
- Filter
- Narrowband: Ha / OIII / SII, or a dual-band / UHC filter
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How to image Lagoon Nebula
- It lies low in the sky for northern observers, so it is best around summer when it is highest. Choose a night with steady air.
- Dual-band or Ha filters work very well on this target and cut skyglow near the horizon.
- At 300 to 500 mm it fits the Lagoon and the Trifid in one frame.
Framing: what focal length?
The focal length at which M8 spans about 60% of the long side of the sensor, leaving room around it. Treat it as a starting point; the right framing is a matter of taste.
| Sensor | Focal length |
|---|---|
| 1-inch sensor (13.2 mm) | about 300 mm |
| APS-C (23.5 mm) | about 540 mm |
| Full frame (36 mm) | about 830 mm |
How high does it climb from your latitude?
The highest point M8 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) | 11° | Stays low |
| 45°N (Minneapolis, Milan) | 21° | Stays low |
| 35°N (Los Angeles, Tokyo) | 31° | Workable |
| 25°N (Miami, Cairo) | 41° | Workable |
| 35°S (Sydney, Santiago) | 79° | High in the sky |
Also worth imaging
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