NGC 6888, the Crescent NebulaNGC 6888, the Crescent Nebula
The Crescent Nebula (NGC 6888) in our Milky Way galaxy, 4,700 light-years away toward the constellation Cygnus. This image is from the light of hydrogen gas (H-alpha) taken from suburban Bloomington, Indiana. It's a pretty cool image, but also a fine demonstration of how stars develop and change (or evolve as astronomers prefer to say). In this case a hot, massive star near the center of the nebula known variously as HD 192163, WR 136, or V12770 Cyg is blowing off its outer layers in a powerful wind. The structure we see is the material is colliding with gas that was blown off in earlier episodes. Where they meet the gas is shocked to very high temperatures.

Tech details:
49 6-minute frames (4hrs 54min total exposure)
GSO 8" f/8 RC OTA
ZWO ASI294MC Pro cooled color CMOS camera
SVBONY H-alpha 7nm filter
ZWO EAF autofocuser
Losmandy GM811G mount
auto-guided: Askar off-axis guider, ZWO ASI174MM Mini guide camera
ZWO ASIAir Plus controller
Processed in Astro Pixel Processor, Lightroom, Photoshop

The Crescent Nebula (NGC 6888) in our Milky Way galaxy, 4,700 light-years away toward the constellation Cygnus. This image was taken from suburban Bloomington, Indiana and captures the light of hydrogen gas.

I think it's a pretty cool image, but also a fine demonstration of the dynamics of the universe and how stars develop and change (or evolve, as astronomers prefer to say). In this case a hot, massive star near the center of the nebula, known as a Wolf-Rayet type star is blowing off its outer layers in a powerful wind. (the star is catalogued variously as HD 192163, WR 136, or V1770 Cygni). The structure we see is where the wind is colliding with gas that was blown off in earlier episodes (also seen as fainter clouds around the brighter bubble), shocking the gas to very high temperatures. Eventually, the surrounding gas may be compressed enough to collapse and form new stars.

Tech details:
49 6-minute frames (4hrs 54min total exposure)
GSO 8" f/8 RC OTA
ZWO ASI294MC Pro cooled color CMOS camera
SVBONY H-alpha 7nm filter
ZWO EAF autofocuser
Losmandy GM811G mount
auto-guided: Askar off-axis guider, ZWO ASI174MM Mini guide camera
ZWO ASIAir Plus controller
Processed in Astro Pixel Processor, Lightroom, Photoshop