The Clamshell's Dark Tenants LDN 949, 952 & Kin in Sh2-119
Sun Sep 20 2026
Everyone photographs the Clamshell for its glow. I ended up photographing what lives inside it. Sh2-119, the Clamshell Nebula, is a sprawling cloud of ionized hydrogen in Cygnus, about 2,200 light-years away, lit by the hot O-type star 68 Cygni. It sits only a couple of degrees from the far more famous North America Nebula, which is part of why it gets passed over. But threaded all through that red-gold gas is a whole population of dark nebula, cold, dense clouds of dust catalogued by Beverly Lynds back in 1962. This frame is centered on a dense knot of them: LDN 949, the largest in the region, alongside LDN 949 and a cluster of smaller neighbors (LDN 942ā953). Backlit by the glowing hydrogen, they read like ink poured into water. I've pulled four of the densest knots out as close-ups below, with a locator showing where each one sits in the frame. š· sh2-119_detail_locator_LDN.png š· sh2-119_LDN949-952.png š· sh2-119_LDN949.png š· sh2-119_LDN948-951.png š· sh2-119_LDN947.png This wasn't the plan. I'd set out to capture the entire Clamshell in one wide field, the whole two-degree shell in a single frame. A hardware problem killed that session before it started, so I fell back to my usual C8. At that focal length the full nebula won't come close to fitting, so instead of a sweeping overview I went hunting for the most interesting square of sky I could find and settled on this pocket, thick with dark structure. The failure turned out to be the better picture: tighter, more detailed, and about the shadows rather than the glowing outline everyone already knows. The OIII in this region seems to be essentially nonexistent and the SII, while usable, is nearly a twin of the Ha, so a traditional palette had nothing to work with. I built it instead as a warm bicolor Ha/SII, then used the Ha itself as luminance to carry all the fine dust-lane and globule detail. Stars are natural RGB. Not the target I intended to shoot, but Iām happy with this instead. Please click through to the other revisions to see different close crops.
About this object
- Type
- Emission Nebula
- Constellation
- Cygnus (the Swan)
- Distance
- ~2,200 light-years
- Also known as
- Clamshell Nebula
- Catalogue designations
- Sh2-119
The Clamshell Nebula (Sh2-119) is a large cloud of glowing hydrogen in Cygnus, lit up by the hot star 68 Cygni. It sits just a couple of degrees from the far more famous North America Nebula, so it often gets passed over. Threaded through its red-gold gas are dark nebulae, cold dusty clouds catalogued by Beverly Lynds in 1962, that read like ink poured into water.
Acquisition
- Antlia 3nm Narrowband H-alpha 36 mm: 60 Ć 3m (3h 0m)
- Antlia 3nm Narrowband Sulfur II 36 mm: 65 Ć 3m (3h 15m)
- Antlia V-Pro Red 36 mm: 90 Ć 30s (45m)
- Antlia V-Pro Green 36 mm: 90 Ć 30s (45m)
- Antlia V-Pro Blue 36 mm: 90 Ć 30s (45m)
- Total integration: 8h 30m
Equipment
- Telescope / Lens: Celestron C8
- Camera: ZWO ASI2600MM Pro
- Mount: Sky-Watcher EQ6
- Filters: Antlia 3nm Narrowband H-alpha 36 mm, Antlia 3nm Narrowband Sulfur II 36 mm, Antlia V-Pro Blue 36 mm, Antlia V-Pro Green 36 mm, Antlia V-Pro Red 36 mm
- Guiding scope: SVBony SV106 60mm Guide Scope
- Guiding camera: ZWO ASI174MM Mini
- Accessories: Celestron 0.63X SCT Reducer (94175), ZWO EFW 7 x 36mm
- Software: Pleiades Astrophoto PixInsight
Astrophotography by David Joyce, AstroDavido.