NGC6888 – the “cosmic brain” in Sii-gilded HOOLRGB

About the Object

NGC 6888, the Crescent Nebula (a.k.a the "cosmic brain") is a very structure-rich emission nebula in the constellation of Cygnus. Like so objects in the NGC catalogue, it was discovered by William Herschel in 1792. The emission nebula is caused by the collision of winds of the Wolf-Rayet star WR136 with slower earlier wind phases resulting in a pretty complex structure.

NGC6888 is usually labeled a typical HOO object for narrowband imaging, as it is comparably weak in SII. Indeed a look at the SII map shows significant emission only in the side lobes, and in some of the surrounding HII emission region (NGC6888 is located  the HII rich extended Sadr region) - this make it an interesting object for @Adam Block's gilding technique: the lobes getting a more orange-yellow color while most of the rest of NGC6888 stays in the typical blue-red of HOO.

Observation Notes

Data were taken on 2024 August 6, 8-13, 15, 16, 19, 28, and 29.

Technical Details

View the full-resolution image together with complete acquisition and processing details on AstroBin.