When to photograph NGC 6357 (Lobster Nebula)
NGC 6357, the Lobster Nebula, is a cluster with nebula in Scorpius, 4′ across.
When to photograph it
From 45° N it never climbs above 30°. It peaks at 11° 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 May to July, with up to 10.0 hours of astronomical darkness above 30° in June. It reaches 89° at its highest.
Framing
At 4′ it is small. Even 4000 mm of focal length leaves it filling less than a third of an APS-C frame, so it suits long focal lengths, small pixels and good seeing.
Filters and the moon
It glows in H-alpha, and often OIII, so a dual-band filter on a color camera or narrowband filters on a mono camera cut light pollution and keep it workable with the moon up. 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 NGC 6357's altitude through tonight, its transit time and its distance from the moon. For sub length, use the exposure calculator.
Nearby targets
- NGC 6334 Cat's Paw Nebula 2.1° away
- NGC 6302 Bug Nebula 3.7° away
- M 6 Butterfly Cluster 3.8° away
- M 7 Ptolemy's Cluster 6.0° away
- M 62 6.4° away
- M 19 9.3° away
Gear that suits NGC 6357
NGC 6357 is only 3.9′ across, so it stays small in any amateur telescope. The longest focal length gives it the most pixels. It shines in H-alpha and OIII, so a dual-band filter on a color camera cuts through light pollution and moonlight.
- Celestron C8 OTA 2032 mm f/10: fills 15% of an APS-C frame's short side View at High Point Scientific
- Optolong L-Ultimate 3 nm 3 nm dual-band, Ha, OIII, for color cameras View at High Point Scientific
- Antlia ALP-T 5 nm 5 nm dual-band, Ha, OIII, for color cameras View at High Point Scientific
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