When to photograph M 20 (Trifid Nebula)
M 20, the Trifid Nebula, is a nebula in Sagittarius, 28′ across at magnitude 8.5. Also listed as NGC 6514.
When to photograph it
From 45° N it never climbs above 30°. It peaks at 22° when it crosses the meridian, low enough that haze and light pollution soften it. It is possible with a clear southern horizon, but hard.
From 35° S the best months are June and July, with up to 9.2 hours of astronomical darkness above 30° in June. It reaches 78° at its highest.
Framing
Its long axis is 28′. It fills 35 to 80% of the short side of an APS-C sensor at about 670 to 1530 mm, and of a full-frame sensor at about 1030 to 2360 mm.
Filters and the moon
Reflection and dark nebulae are broadband targets. They need dark, moon-free nights and plenty of integration time. The dark sky calendar shows which nights this month are moon-free where you are.
Plan it for tonight
Dates and times depend on your exact location. The imaging planner shows M 20's altitude through tonight, its transit time and its distance from the moon. For sub length, use the exposure calculator.
Nearby targets
- M 21 0.6° away
- M 8 Lagoon Nebula 1.4° away
- M 23 4.2° away
- M 28 5.3° away
- M 24 Sagittarius Star Cloud 5.6° away
- M 18 7.1° away
Gear that suits M 20
M 20 is 28′ along its long axis. These frame it on an APS-C sensor with room to crop.
- Sky-Watcher Esprit 120ED 840 mm f/7: fills 44% of an APS-C frame's short side View at High Point Scientific
- Sky-Watcher Quattro 200P 800 mm f/4: fills 42% of an APS-C frame's short side View at High Point Scientific
- Sky-Watcher 130PDS 650 mm f/5: fills 34% of an APS-C frame's short side View at High Point Scientific
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