When to photograph M 97 (Owl Nebula)
M 97, the Owl Nebula, is a planetary nebula in Ursa Major, 4′ across at magnitude 9.9. Also listed as NGC 3587.
When to photograph it
From 45° N the best months are January to March, with up to 10.3 hours of astronomical darkness above 30° in February. It reaches 80° at its highest. It never sets from this latitude, so some imaging is possible all year.
From 35° S it never rises.
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
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 M 97's altitude through tonight, its transit time and its distance from the moon. For sub length, use the exposure calculator.
Nearby targets
- M 108 0.8° away
- M 109 6.5° away
- NGC 4088 8.9° away
- M 40 Winnecke 4 9.8° away
- M 106 12.6° away
- IC 2574 Coddington's Nebula 14.4° away
Gear that suits M 97
M 97 is only 3.6′ 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 14% 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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