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Leo Triplet (M65)

spiral galaxy in Leo

M65 is a tilted spiral galaxy in Leo that forms the Leo Triplet with M66 and NGC 3628. All three fit in about a degree, making it one of the best galaxy groups for a mid-length lens.

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Approximate size and shape, drawn to scale. Not a photograph.

// Key facts

Catalog: M65
Type: spiral galaxy
Constellation: Leo
Size: 10′ across
Brightness: Magnitude 9.3
Distance: about 35 million light-years
Peak month (any location): Mar
Typical prime months: Dec to May
Difficulty: Intermediate
Filter: No filter (broadband); a light-pollution filter is optional

// For your location

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How to image Leo Triplet

A frame of about 1.5 degrees (roughly 700 to 800 mm on APS-C) captures all three triplet galaxies.
M65 and M66 are bright, but NGC 3628 is fainter and shows its dust lane with long exposure.
Spring evenings are best from northern sites.

Framing: what focal length?

M65 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 12%
2,000 mm	about 25%
3,000 mm	about 37%

How high does it climb from your latitude?

The highest point M65 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)	48°	Workable
45°N (Minneapolis, Milan)	58°	Workable
35°N (Los Angeles, Tokyo)	68°	High in the sky
25°N (Miami, Cairo)	78°	High in the sky
35°S (Sydney, Santiago)	42°	Workable

Also worth imaging

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