new icn messageflickr-free-ic3d pan white
Crescent Nebula (NGC6888) close up in Hα/SII/OIII+rgb | by Carballada
Back to photostream

Crescent Nebula (NGC6888) close up in Hα/SII/OIII+rgb


Crescent Nebula revisited three years later with better equipment, better skies and some more skills on my side.


The Crescent Nebula (also known as NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in the constellation Cygnus, about 5000 light-years away from Earth. It was discovered by William Herschel in 1792. It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 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. (Wikipedia)


That's the first image after this long period, in part due the COVID in part because the long integration time that I wanted and how short are these summer nights.


It was eleven nights with two rigs resulting on 75 hours of integration time. My longest integration time so far.


Technical card

Imaging telescopes or lenses:Teleskop Service TS Photoline 107mm f/6.5 Super-Apo , Altair Astro RC250-TT 10" RC Truss Tube


Imaging cameras:ZWO ASI183MM-Cool , ZWO ASI1600MM-Cool


Mounts:Skywatcher EQ6R Pro , Mesu 200 Mk2


Guiding telescopes or lenses:Celestron OAG Deluxe , Teleskop Service TSOAG9 Off-Axis Guider


Guiding cameras:ZWO ASI174 Mini , ZWO ASI290 Mini


Focal reducers:Riccardi Reducer/Flattener 0.75x , Telescope-Service TS 2" Flattener


Software:Pleiades Astrophoto PixInsight , Seqence Generator Pro


Filters:Astrodon O-III 36mm - 5nm , Astrodon S-II 36mm - 5nm , Astrodon R Gen.2 E-series 36mm , Astrodon G Gen.2 E-series 36mm , Astrodon B Gen.2 E-series 36mm , Astrodon HA 36mm - 5nm , Astrodon L Gen.2 E-series 36mm


Accessory:ZWO EFW , MoonLite NiteCrawler WR30 , TALON6 R.O.R , MoonLite CSL 2.5" Focuser with High Res Stepper Motor


Dates:June 21, 2020 , June 22, 2020 , June 23, 2020 , June 29, 2020 , July 18, 2020



Astrodon B Gen.2 E-series 36mm: 50x120" (gain: 75.00) -20C bin 1x1

Astrodon G Gen.2 E-series 36mm: 50x120" (gain: 75.00) -20C bin 1x1

Astrodon HA 36mm - 5nm: 209x600" (gain: 200.00) -20C bin 1x1

Astrodon O-III 36mm - 5nm: 105x600" (gain: 183.00) -15C bin 1x1

Astrodon R Gen.2 E-series 36mm: 50x120" (gain: 75.00) -20C bin 1x1

Astrodon S-II 36mm - 5nm: 106x600" (gain: 183.00) -15C bin 1x1


Integration: 75.0 hours


Avg. Moon age: 7.92 days


Avg. Moon phase: 15.25% job: 3721258


RA center: 20h 12' 6"


DEC center: +38° 21' 0"


Pixel scale: 1.007 arcsec/pixel


Orientation: -89.431 degrees


Field radius: 0.408 degrees


Resolution: 2328x1760


Locations: AAS Montsec, Àger, Lleida, Spain


Data source: Own remote observatory


Remote source: Non-commercial independent facility

47 faves
Uploaded on August 2, 2020