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M77
spiral galaxy in Cetus
M77 is a barred spiral in Cetus with a very bright, active nucleus, making it a Seyfert galaxy. Its bright core shines even through some light pollution, and the tightly wound arms surround it.
Save your telescope or lens on the planner to lay your camera frame over this diagram.
// Key facts
- Catalog
- M77
- Type
- spiral galaxy
- Constellation
- Cetus
- Size
- 7′ across
- Brightness
- Magnitude 8.9
- Distance
- about 47 million light-years
- Peak month (any location)
- Oct
- Typical prime months
- Aug to Jan
- 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 M77
- At 7 arcminutes, use 1,200 to 2,000 mm.
- The bright core can clip, so blend in short exposures to preserve detail.
- It is best in autumn and early winter evenings.
Framing: what focal length?
M77 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 9% |
| 2,000 mm | about 17% |
| 3,000 mm | about 26% |
How high does it climb from your latitude?
The highest point M77 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) | 35° | Workable |
| 45°N (Minneapolis, Milan) | 45° | Workable |
| 35°N (Los Angeles, Tokyo) | 55° | Workable |
| 25°N (Miami, Cairo) | 65° | High in the sky |
| 35°S (Sydney, Santiago) | 55° | Workable |
Also worth imaging
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