IC 1318 B/C (Cygnus)
Fig. 1 - Formed like two glowing cosmic wings separated by a long dark dust alley: The diffuse emission nebula IC 1318 in Cygnus, photographed with an 8-inch f/4 Newtonian reflector on a ZWO AM5 mount.
| Object name: | Constellation: | Coordinates (2000): | Apparent size: | Visual brightness: |
|---|---|---|---|---|
| IC 1318 B/C (LBN 249 / LBN 245) | Cygnus | 20h27m / +40°08' | 1.3° x 1.0° | - |
The diffuse emission nebula IC 1318 B/C (LBN 249 & LBN 245, "Sadr Region", "Gamma Cygni Nebula", "Butterfly Nebula") seemingly surrounding the star γ Cygni (Sadr) at the center of Cygnus's cross in the constellation of Cygnus.
The emission nebula and H-II region IC 1318 B/C is located approximately 4,900 light-years from Earth and has an extent of 100 light-years. Since the star γ Cygni (Sadr) is thought to be at a distance of 1,500 light-years, the nebula and the star are unassociated and Sadr is not the cause of the emission nebula's glow. IC 1318 is divided into three parts, IC 1318 A, IC 1318 B and IC 1318 C, which differ from each other. IC 1318 B and IC 1318 C are separated by the 20 light-years-wide dark cloud LDN 889 (see labeled image Fig. 2 further down the page). IC 1318 is sometimes called the Butterfly Nebula, but the nebula should not be confused with NGC 6302, which is also known as the Butterfly Nebula and is a planetary nebula about 3,800 light-years away in the constellation Scorpius. (source: Wikipedia).
Exposure time: 5h 42min (114x3min) at gain 100 and -10°C, taken on May 19 and May 29/30, 2025. Processing with Astro Pixel Processor (APP) and Photoshop. Darks, flats, bias and darkflats were used.
Equipment: Cooled ASI 2600MC Pro camera, TeleVue Paracorr Type II coma corrector, 8" f/4 "ONTC" Newtonian telescope riding on a ZWO AM5 Strain Wave Mount, ZWO OAG-L off axis system, ASI 174MM Mini guide camera, ASIAIR Plus.
Fig. 2 - Annotated image of IC 1318 B/C. IC 1318 B and IC 1318 C are separated by the dark cloud LDN 889. In IC 1318 C, the dark nebula Barnard 347 is visible. The dark nebula in IC 1318 B is sometimes referred to as TGU H469 P2, as listed in the Tokyo Gakugei University catalog of dark clouds.
Fig. 3 - Search chart for IC 1318. Copyright 2025 'The Mag-7 Star Atlas Project', www.siaris.net. The map is modified (IC 1318 is not included on the original map).