Sh 2-119 – Clamshell Nebula
Sh 2-119 is an extensive, faint emission nebula in the constellation Cygnus, approximately three degrees east of the North America Nebula and about 2,200 light-years away. Popularly known as the Clamshell Nebula, it appears to surround the bright star 68 Cygni, a massive, extremely hot O-type star whose intense ultraviolet radiation ionises the surrounding gas. The nebula displays a complex structure formed by two large shells on either side of 68 Cygni, with emission arcs, delicate filaments, cavities and dark clouds silhouetted against Cygnus’s dense star field. In the image, the golden hydrogen structures contrast with the bluish oxygen emissions surrounding 68 Cygni, highlighting the effect of its radiation and stellar winds on the interstellar gas. The image was processed in narrowband using an HOO combination and treated with PixInsight’s NarrowbandNormalization script to balance and enhance the different emissions.
General information
- Constellation
- Cygnus
- Category
- Nebulae
- Date
- 28 July 2026
Capture
- Total time
- 6h 00min
- Subframes
- 300s (Ha: 36x, OIII: 36x) bin1
- Gain / Offset
- 125 / 30
- Calibration
- 30 flat frames, 30 dark-flat frames and 40 library dark frames, without bias frames
Equipment
- Telescope
- TS102ED f/5.6
- Camera
- ASI294MM at -10ºC
- Filters
- Ha and OIII Astronomik, 6 nm
- Mount
- Sky Watcher Wave 150i
- Guiding
- PHD2, Guide scope 60mm/f4 + ASI220MM + PegasusAstro UCH + PPBMicro
- Focuser
- ZWO EAF
- Filter wheel
- ZWO EFW 7pos
Processing and environment
- Processing
- Stacked and post-processed with PixInsight 1.9.4
- Acquisition
- NINA
- Location
- l'Ampolla
- Sky
- Bortle 4