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M72
globular cluster in Aquarius
M72 is a faint, distant globular cluster in Aquarius. A small group of stars, M73, sits just over a degree away, and the two can share a mid-sized frame.
Save your telescope or lens on the planner to lay your camera frame over this diagram.
// Key facts
- Catalog
- M72
- Type
- globular cluster
- Constellation
- Aquarius
- Size
- 6′ across
- Brightness
- Magnitude 9.3
- Distance
- about 53,000 light-years
- Peak month (any location)
- Aug
- Typical prime months
- May to Oct
- Difficulty
- Advanced
- 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 M72
- A frame of about 1.5 to 2 degrees takes in both M72 and M73.
- It is distant and faint, so a longer total exposure is needed for a good halo.
- At dec -13 it is moderately low from northern sites, in the autumn evening sky.
Framing: what focal length?
M72 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 7% |
| 2,000 mm | about 15% |
| 3,000 mm | about 22% |
How high does it climb from your latitude?
The highest point M72 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) | 22° | Stays low |
| 45°N (Minneapolis, Milan) | 32° | Workable |
| 35°N (Los Angeles, Tokyo) | 42° | Workable |
| 25°N (Miami, Cairo) | 52° | Workable |
| 35°S (Sydney, Santiago) | 68° | High in the sky |
Also worth imaging
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