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Cigar Galaxy (M82)
irregular galaxy in Ursa Major
The Cigar Galaxy is a starburst galaxy: it is forming stars many times faster than the Milky Way, and the burst blows red hydrogen out of its disc in two long plumes. At eleven arcminutes it is much smaller than M81 but far more dramatic in a longer exposure.
Save your telescope or lens on the planner to lay your camera frame over this diagram.
// Key facts
- Catalog
- M82
- Type
- irregular galaxy
- Constellation
- Ursa Major
- Size
- 11′ across
- Brightness
- Magnitude 8.4
- Distance
- about 12 million light-years
- Peak month (any location)
- Feb
- Typical prime months
- Dec to May
- Difficulty
- Intermediate
- 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 Cigar Galaxy
- The red plumes only show in hydrogen-alpha. Add Ha data to your color image, or use a one-shot camera with a dual-band filter for a hint.
- Use 800 mm or more to make it fill a useful part of the frame.
- M81 is in the same wide field if you prefer a pair portrait.
Framing: what focal length?
M82 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 14% |
| 2,000 mm | about 27% |
| 3,000 mm | about 41% |
How high does it climb from your latitude?
The highest point M82 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) | 75° | High in the sky |
| 45°N (Minneapolis, Milan) | 65° | High in the sky |
| 35°N (Los Angeles, Tokyo) | 55° | Workable |
| 25°N (Miami, Cairo) | 45° | Workable |
| 35°S (Sydney, Santiago) | below horizon | Never rises |
Also worth imaging
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