When to photograph NGC 7293 (Helix Nebula)
NGC 7293, the Helix Nebula, is a planetary nebula in Aquarius, 16′ across at magnitude 7.3. Also listed as C 63.
When to photograph it
From 45° N it never climbs above 30°. It peaks at 24° 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 August and September, with up to 8.8 hours of astronomical darkness above 30° in August. It reaches 76° at its highest.
Framing
Its long axis is 16′. It fills 35 to 80% of the short side of an APS-C sensor at about 1150 to 2630 mm, and of a full-frame sensor at about 1770 to 4050 mm.
Filters and the moon
Planetary nebulae are bright in OIII and H-alpha and small, so narrowband works and the moon matters less. Short subs help with the bright core. 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 7293's altitude through tonight, its transit time and its distance from the moon. For sub length, use the exposure calculator.
Nearby targets
Gear that suits NGC 7293
NGC 7293 is 16′ 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 62% of an APS-C frame's short side View at High Point Scientific
- Celestron EdgeHD 8 OTA 2032 mm f/10: fills 62% of an APS-C frame's short side View at High Point Scientific
- Sky-Watcher Esprit 120ED 840 mm f/7: fills 26% 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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