NGC6888 (Crescent Nebula)
My mid-September 2021 photo of NGC6888 aka Crescent Nebula.
Crescent Nebula is a 25 light-year-wide emission nebula in constellation Cygnus. It is formed by the collision of stellar winds from a Wolf-Rayet star – known as WR 136. The nebula is about 5000 light-years away from Earth. The WR 136 is nearing the end of its life and is expected to explode as a supernova within a few hundred thousand years.
Here I used H-S-O for R-G-B mapping with Ha, SII, and OIII filter data. Thus, on this image you can see hydrogen as red and oxygen as blue.
Home observatory-on-balcony in Cottbus, Germany.
- Light pollution: with SQM of 19.89 mag./arc sec2 center of Cottbus is around Bortle 5 sky.
- Imaging optics: William Optics ZenithStar 80mm f/6.8 ED Refractor and WO Flat6AIII (0.8x)
- Mount: SW HEQ5 PRO
- Camera: ZWO ASI-294MM
- Filters: ZWO Ha, OIII, SII (7nm)
- Guiding: WO 50mm f/4 Guide Scope and ASI120MM-Mini
- Other tech: ZWO EFW, ZWO EAF
- Imaging @ Gain: 120 | Cooling: -10C | Bin1 (8288*5644px)
- Integration: ca. 4 hours; 300" exposures per image all filters.
- Software: PixInsight, Stellarium