Crescent Nebula: NGC 6888
Third time revisiting this amazing target. Added some Sii and rgb light as well as updated processing.
"NGC 6888, also known as the Crescent Nebula, is an emission nebula located in the constellation Cygnus. It was discovered by William Herschel in 1792 and is approximately 4,700 light-years away from Earth. Here’s an overview of its key features:
1. Shape and Structure
Crescent Shape: The nebula has a distinct crescent or arc shape, which is the result of the interaction between fast stellar winds and the slower-moving material ejected by its central star.
Shell-like Structure: NGC 6888 consists of a shell of gas that is being illuminated by the hot, massive central star, creating the beautiful glowing appearance. It spans about 25 light-years across.
2. Central Star – Wolf-Rayet Star
At the heart of NGC 6888 is a massive, hot star called WR 136 (HD 192163), a Wolf-Rayet star. Wolf-Rayet stars are known for their intense stellar winds and their short, turbulent life cycles.
WR 136 has ejected a significant amount of its outer layers, forming the nebula. The interaction between these ejected materials and the powerful stellar winds is what shapes the Crescent Nebula.
3. Formation Process
The Crescent Nebula was formed by the stellar wind from WR 136 colliding with material it had ejected earlier when it was a red supergiant. The faster wind from the current Wolf-Rayet phase compresses the earlier, slower-moving material, creating the shockwaves that result in the glowing, intricate structures of the nebula.
4. Emission Nebula
NGC 6888 is categorized as an emission nebula, meaning it glows due to the ionization of gas, primarily hydrogen. The ultraviolet radiation from WR 136 excites the gas, causing it to emit light, predominantly in red and green colors, making it a popular target for astrophotographers.
5. Lifespan
WR 136 is expected to end its life in a supernova explosion. The Crescent Nebula represents a transitional phase in the life of a massive star as it sheds its outer layers before collapsing in on itself." --synthesized from various sources
Askar 120APO: 840mm f/7
ZWO ASI533MC Color Camera at -10C
55xUvIr@1m
ZWO ASI533MM Mono Camera at -10C
20xHa, 57xOiii@5m
12xSii@10m
Guided on ZWO AM5
Processed with PixInsight, Ps
Crescent Nebula: NGC 6888
Third time revisiting this amazing target. Added some Sii and rgb light as well as updated processing.
"NGC 6888, also known as the Crescent Nebula, is an emission nebula located in the constellation Cygnus. It was discovered by William Herschel in 1792 and is approximately 4,700 light-years away from Earth. Here’s an overview of its key features:
1. Shape and Structure
Crescent Shape: The nebula has a distinct crescent or arc shape, which is the result of the interaction between fast stellar winds and the slower-moving material ejected by its central star.
Shell-like Structure: NGC 6888 consists of a shell of gas that is being illuminated by the hot, massive central star, creating the beautiful glowing appearance. It spans about 25 light-years across.
2. Central Star – Wolf-Rayet Star
At the heart of NGC 6888 is a massive, hot star called WR 136 (HD 192163), a Wolf-Rayet star. Wolf-Rayet stars are known for their intense stellar winds and their short, turbulent life cycles.
WR 136 has ejected a significant amount of its outer layers, forming the nebula. The interaction between these ejected materials and the powerful stellar winds is what shapes the Crescent Nebula.
3. Formation Process
The Crescent Nebula was formed by the stellar wind from WR 136 colliding with material it had ejected earlier when it was a red supergiant. The faster wind from the current Wolf-Rayet phase compresses the earlier, slower-moving material, creating the shockwaves that result in the glowing, intricate structures of the nebula.
4. Emission Nebula
NGC 6888 is categorized as an emission nebula, meaning it glows due to the ionization of gas, primarily hydrogen. The ultraviolet radiation from WR 136 excites the gas, causing it to emit light, predominantly in red and green colors, making it a popular target for astrophotographers.
5. Lifespan
WR 136 is expected to end its life in a supernova explosion. The Crescent Nebula represents a transitional phase in the life of a massive star as it sheds its outer layers before collapsing in on itself." --synthesized from various sources
Askar 120APO: 840mm f/7
ZWO ASI533MC Color Camera at -10C
55xUvIr@1m
ZWO ASI533MM Mono Camera at -10C
20xHa, 57xOiii@5m
12xSii@10m
Guided on ZWO AM5
Processed with PixInsight, Ps