When to photograph NGC 2359 (Thor's Helmet)
NGC 2359, the Thor's Helmet, is an emission nebula in Canis Major, 9′ x 6′ across.
When to photograph it
From 45° N the best months are November to February, with up to 2.2 hours of astronomical darkness above 30° in February. It reaches 32° at its highest.
From 35° S the best months are December to February, with up to 6.3 hours of astronomical darkness above 30° in January. It reaches 68° at its highest.
Framing
Its long axis is 9′. It fills 35 to 80% of the short side of an APS-C sensor at about 2090 to 4770 mm, and of a full-frame sensor at about 3210 to 7330 mm.
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 2359's altitude through tonight, its transit time and its distance from the moon. For sub length, use the exposure calculator.
Nearby targets
- NGC 2360 Caroline's Cluster 2.4° away
- IC 2177 Seagull Nebula 4.4° away
- M 47 4.6° away
- M 46 5.9° away
- M 50 6.2° away
- NGC 2506 10.4° away
Gear that suits NGC 2359
NGC 2359 is 9.0′ along its long axis. These frame it on an APS-C sensor with room to crop. 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 34% of an APS-C frame's short side View at High Point Scientific
- Celestron EdgeHD 8 OTA 2032 mm f/10: fills 34% 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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