NGC 6888 cropped: taken on 7-14-2023
"Crescent Nebula"
The Crescent Nebula (NGC 6888) is an emission nebula in the constellation Cygnus, about 5000 light-years away from Earth. It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 colliding with and energizing the slower moving wind ejected by the star when it became a red giant over 250,000 years ago. The result of the collision is a shell. and two shock waves, one moving outward and one moving inward. The inward moving shock wave heats the stellar wind to X-ray-emitting temperatures
file: NGC6888-240sX36AP130f4d7p1- 7142023a1a.jpg

Photographic Data
telescope:
Astro-Physics 130 mm (5.1-inch) f/6 triplet refractor focally reduced to f/4.7 (FL= 616 mm)

mount:
ZWO AM5 harmonic/strainwave
Mount Guide Settings in Asiair Plus:
Calibrate Step: 5,000 ms
Dec Duration: 3,000 ms
RA Duration: 2,000 ms
Aggression: 50% for both RA & Dec
Exposure time for guiding: 1 second

Guiding hardware:
SVBony 60 mm f/4 guidescope (fl=240 mm)
Guide Camera: ZWO ASI662MC color planetary camera (2.97 micron pixels)

imaging camera:
ZWO ASI533MC-Pro one-shot color astro-camera cooled to 14-degrees F with Optolong L-eNhanced nebular filter

controller/computer
ZWO Asiair Plus via WiFi to Samsung S7+ tablet
.
.exposures:
240 seconds X 37 (148-minutes or 2.46 hours)

processing
Stacked in Asiair Plus and cropped and post-processed in Adobe Photoshop Elements
.
photographic site:
West Los Angeles
http://mstecker.com/pages/chhouses_fp.htm
(Bortle 9 light polluted sky)

Photographic Data
telescope:
Astro-Physics 130 mm (5.1-inch) f/6 EDF Starfire triplet refractor with field flattener at f/6.7 (FL= 877 mm)

mount:
ZWO AM5 harmonic/strainwave
Mount Guide Settings in Asiair Plus:
Calibrate Step: 1,000 ms
Dec Duration: 600 ms
RA Duration: 400 ms
Aggression: 50% for both RA & Dec
Exposure time for guiding: 1 second

imaging camera:
ZWO ASI2600MC Duo camera with Sony IMX571 26-megapixel imaging sensor cooled to 14-degrees C

filter:
Optolong L-eNhanced nebular filter

guiding:
Mini 220 guide sensor on ZWO ASI2600MC Duo camera

controller/computer
ZWO Asiair Plus via WiFi to Samsung S7+ tablet
.
exposures:
180 seconds X 54 (162-minutes or 2.7 hours)

processing
Stacked in Asiair Plus and cropped and post-processed in Adobe Photoshop Elements
.
photographic site:
West Los Angeles California (backyard)