Sh2-216 "The Second Planetary Nebula" and SH2-221

 Posted: Jan 12th, 2026
Technical Info
Telescope/Lens: Askar SQA55 55 мм f/4.8 & Samyang 135mm f/2.0 ED
Camera: Touptek IMX571 C & QHYCCD QHY5III585M
Mount: JUWEI-14
Guide Scope: 30мм
Guide Camera: T7m
Software: NINA, Pixlnsight, ФШ
Accessories: Колесо touptek,AFW,8*1,25inch, USB3.0 разводка питания, хаб.
Exposure:
52 x 600" ISO/Gain: 152 - Optolong L-Ultimate
12 x 600" ISO/Gain: 9 - H
23 x 300" ISO/Gain: 9 - H
Orange, Bortle 6 zone:
 Ekaterinburg Rayon Ozera Gluhoe, Russia
 Jan 9th, 2026
12 h 35 m
25
Extremely faint objects, especially for winter and an orange light pollution zone.
A dual-cannon setup on a single mount.
1. Askar SQA55 55mm f/4.8 telescope with a Touptek IMX571 C camera and an Optolong L-Ultimate filter.
2. Samyang 135mm f/2.0 ED lens with a QHY5III585M camera and a Touptek AFW 8×1.25" filter wheel.

I tried to synchronize the two scopes, but after losing a night, I realized it was nonsense—the cameras wouldn’t wait for each other.
So, I ran one with 10-minute subs and dithering every 3 frames, and the other with 5-minute subs, ending up with about every 6th frame from that camera in the trash.

Now about the object—it’s on AstroBin but not here.
Sh2-221 (left) is a supernova remnant located about 2,600 light-years away from the star that exploded roughly 6,000 years ago. Its diameter is about 130 light-years. The star, once very similar to our Sun and which created the planetary nebula Sh2-216 (right), began slowly dying half a million years ago, making it ancient by planetary nebula standards. Sh2-216 is much closer, about 400 light-years away, and significantly smaller—11 light-years in diameter. It is the second-closest known planetary nebula, as well as the largest and oldest.

The yellow-orange patch above Sh2-221 is Sh2-217. It is part of a larger star-forming region and contains about 4,100 solar masses of material. The star-forming region mentioned above is very young for such objects, only 4 million years old. Sh2-217 is about 13,700 light-years away and spans about 35 light-years at its widest point. The smaller object Sh2-219, which appears to sit on the right shoulder of Sh2-221, is part of the same star-forming region as Sh2-217 and lies at roughly the same distance from us. The emission nebula BFS 44/LBN 755 in the lower part of the frame between the two large objects is also part of the same star-forming region.

Just a couple of nights so far—I’ll keep collecting more data.
Resolution: 5900x3368 px
Scale: 6841 KB
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Comments

Good job, Oleg!
It's an interesting object, but can't you add oxygen?
Today, at 11:39 Reply
Oleg Novoselov Replied to Ryjov Aleksey
Let's keep adding data, I plan to work on this project all winter and aim to accumulate about 50 hours of exposure.
Today, at 11:46 Reply
Ryjov Aleksey Replied to Oleg Novoselov
The object is definitely worth it. Clear skies.
Today, at 12:21 Reply

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