When to photograph IC 2391 (Omicron Velorum Cluster)
IC 2391, the Omicron Velorum Cluster, is an open cluster in Vela, 29′ across at magnitude 2.5. Also listed as C 85.
When to photograph it
From 45° N it never rises.
From 35° S the best months are January to March, with up to 7.5 hours of astronomical darkness above 30° in February. It reaches 72° at its highest.
Framing
Its long axis is 29′. It fills 35 to 80% of the short side of an APS-C sensor at about 640 to 1470 mm, and of a full-frame sensor at about 990 to 2270 mm.
Filters and the moon
Clusters are broadband targets, but bright ones tolerate some moonlight and light pollution. Short subs keep the brightest stars from clipping. 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 IC 2391's altitude through tonight, its transit time and its distance from the moon. For sub length, use the exposure calculator.
Nearby targets
- NGC 2867 7.8° away
- NGC 2516 9.6° away
- NGC 2477 16.7° away
- NGC 3201 16.9° away
- NGC 3372 Carina Nebula 18.3° away
- IC 2602 Southern Pleiades 19.2° away
Gear that suits IC 2391
IC 2391 is 29′ 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 46% of an APS-C frame's short side View at High Point Scientific
- Sky-Watcher Quattro 200P 800 mm f/4: fills 43% of an APS-C frame's short side View at High Point Scientific
- Sky-Watcher 130PDS 650 mm f/5: fills 35% of an APS-C frame's short side View at High Point Scientific
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