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Hidden Galaxy (IC 342)
spiral galaxy in Camelopardalis
The Hidden Galaxy is a large, face-on spiral in Camelopardalis that would be one of the showpieces of the sky if it were not hiding behind the dust and stars of our own Milky Way. Dimming from that foreground makes it much fainter than its size suggests. Good images show tidy spiral arms and a bright core.
Save your telescope or lens on the planner to lay your camera frame over this diagram.
// Key facts
- Catalog
- IC 342
- Also known as
- C 5, Caldwell 5
- Type
- spiral galaxy
- Constellation
- Camelopardalis
- Size
- 21′ across
- Brightness
- Magnitude 9.1
- Distance
- roughly 10 million light-years
- Peak month (any location)
- Nov
- Typical prime months
- Sep to Jan
- Difficulty
- Advanced
- Filter
- No filter (broadband); a light-pollution filter is optional
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 Hidden Galaxy
- At about 21 arcminutes it needs 1,000 to 2,000 mm to fill the frame nicely.
- The glow is faint and low in contrast, so aim for a dark sky and many hours of exposure.
- Keep flats clean: gradients from light pollution or vignetting easily swamp the outer arms.
Framing: what focal length?
The focal length at which IC 342 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 1300 mm |
| APS-C (23.5 mm) | about 2310 mm |
| Full frame (36 mm) | about 3540 mm |
How high does it climb from your latitude?
The highest point IC 342 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) | 77° | High in the sky |
| 45°N (Minneapolis, Milan) | 67° | High in the sky |
| 35°N (Los Angeles, Tokyo) | 57° | Workable |
| 25°N (Miami, Cairo) | 47° | Workable |
| 35°S (Sydney, Santiago) | below horizon | Never rises |
Also worth imaging
Want a GO / NO-GO verdict for tonight, with clouds, moon, seeing and a full dark-window timeline?
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