Go / no go for deep skyGo / no go for deep sky imaging
M34
open cluster in Perseus
M34 is a large, loose open cluster in Perseus, easy to see in a pair of binoculars and just visible to the naked eye from a dark site. Its stars are bright and well spread, making it a rewarding wide-field target.
Save your telescope or lens on the planner to lay your camera frame over this diagram.
// Key facts
- Catalog
- M34
- Type
- open cluster
- Constellation
- Perseus
- Size
- 35′ across
- Brightness
- Magnitude 5.5
- Distance
- about 1,500 light-years
- Peak month (any location)
- Oct
- Typical prime months
- Aug to Jan
- Difficulty
- Beginner
- Filter
- No filter (broadband)
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 M34
- At 35 arcminutes, 400 to 700 mm is ideal.
- It is high in the sky for northern observers on autumn and winter nights.
- The Double Cluster is in the same constellation if you want a second Perseus target.
Framing: what focal length?
The focal length at which M34 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 780 mm |
| APS-C (23.5 mm) | about 1380 mm |
| Full frame (36 mm) | about 2120 mm |
How high does it climb from your latitude?
The highest point M34 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) | 78° | High in the sky |
| 45°N (Minneapolis, Milan) | 88° | High in the sky |
| 35°N (Los Angeles, Tokyo) | 82° | High in the sky |
| 25°N (Miami, Cairo) | 72° | High in the sky |
| 35°S (Sydney, Santiago) | 12° | Stays low |
Also worth imaging
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