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M48
open cluster in Hydra
M48 is a large, bright open cluster in Hydra. It was a mystery for a long time because Messier recorded its position wrongly, so people could not find it until it was identified in the twentieth century. Its stars are spread across a broad field.
Save your telescope or lens on the planner to lay your camera frame over this diagram.
// Key facts
- Catalog
- M48
- Type
- open cluster
- Constellation
- Hydra
- Size
- 54′ across
- Brightness
- Magnitude 5.8
- Distance
- about 2,000 light-years
- Peak month (any location)
- Jan
- Typical prime months
- Nov to Apr
- 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 M48
- At 54 arcminutes, 250 to 400 mm gives a good frame.
- It sits in a sparse part of the sky, so the background is clean.
- Dec -6 makes it moderately high for most observers in late winter and spring.
Framing: what focal length?
The focal length at which M48 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 500 mm |
| APS-C (23.5 mm) | about 900 mm |
| Full frame (36 mm) | about 1380 mm |
How high does it climb from your latitude?
The highest point M48 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) | 29° | Stays low |
| 45°N (Minneapolis, Milan) | 39° | Workable |
| 35°N (Los Angeles, Tokyo) | 49° | Workable |
| 25°N (Miami, Cairo) | 59° | Workable |
| 35°S (Sydney, Santiago) | 61° | High in the sky |
Also worth imaging
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