Location / Date

Zellerndorf, Aug and Sept 2015

Telescope / Mount / Guiding

ASA 10" Astrograph, ASA 3" Wynne Corrector
ASA DDM60, no Guiding

Camera / Exposure

FLI ML8300, FLI CFW-2-7 Filter Wheel
Hα 5nm Astrodon Filter 15 x 20min
OIII 3nm Astrodon Filter 14 x 20min
SII 3nm Astrodon Filter 14 x 20min
total 14h 20min

Processing

Theli, Fitswork, PixInsight, Photoshop

The image is in mapped colors: SII = Red, Hα = Green and OIII = Blue
known as Hubble (HST) Palette

Notes

The Propeller Nebula (Simeis 57, MRSL 497 or incorrectly DWB 111) is a part of the much larger emission nebula complex Cygnus X in the constellation Cygnus.

It was catalogued first in the early 1950s by astronomers at the Crimean Astrophysical Observatory at Simeiz, Ukraine, as the 57th object in a catalogue containing 306 HII regions.
The Propeller Nebula is often incorrectly referred as DWB 111, but DWB 111 identifies only the southern (lower) arm, while the northern one is DWB 119. The DWB catalog, developed by H. R. Dickel, H. Wendker and J. H. Bieritz in 1969, cataloging 193 distinct objects as part of their study of Hα-emission nebula in the Cygnus X region of the sky.

This nebula radiates mostly in Hα, some SII and is very faint in OIII.