When to photograph M 72
M 72 is a globular cluster in Aquarius, 5′ across at magnitude 9. Also listed as NGC 6981.
When to photograph it
From 45° N the best months are July to September, with up to 2.7 hours of astronomical darkness above 30° in September. It reaches 32° at its highest.
From 35° S the best months are July and August, with up to 8.2 hours of astronomical darkness above 30° in July. It reaches 68° at its highest.
Framing
At 5′ 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
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 M 72's altitude through tonight, its transit time and its distance from the moon. For sub length, use the exposure calculator.
Nearby targets
- M 73 1.3° away
- NGC 7009 Saturn Nebula 2.9° away
- M 75 14.7° away
- M 2 15.3° away
- M 30 15.4° away
- NGC 6822 Barnard's Galaxy 16.8° away
Gear that suits M 72
M 72 is only 4.5′ across, so it stays small in any amateur telescope. The longest focal length gives it the most pixels.
- Celestron C8 OTA 2032 mm f/10: fills 17% of an APS-C frame's short side View at High Point Scientific
Retailer links are affiliate links. If you buy through one, the site may earn a commission at no extra cost to you. Details