Propeller Nebula

Image Description and Details : The Propeller nebula (also known as DWB 111 or Simeis 57) is a emission H-alfa nebula in Cygnus constellation in the center of a triangle made by Deneb, Sadr and Delta-Cyg.
DWB and Simies designations are not so commonly known. The Simeis Catalog was created in the 1950s by the Crimean Astrophysical Observatory in Simeis, Ukraine. This catalog is focused on HII regions and documented 306 of them. The Propeller Nebula is item 57 in this catalog.
The DWB catalog was created in the 1960s by H. R. Dickel, H. Wendker, and J. H. Bieritz, and it cataloged the HII regions they were studying in the Cygnus X Complex. While DWB 111 is often used as the designation for the Propeller, it only deals with the southern arm of the Propeller, while DWB 119 deals with the northern arm. So you can call the Propeller Nebula DWB 111/119 or Semeis 57.

Konus 200/1000 @960mm, f/4.8
Qhy168c @-5 °C
Sky-Watcher Eq6r Pro mount
Optolong L_Ultimate 126x300" (gain 11, offset 60)
SvBony UV/IR-cut 161x30 (gain 1, offset 30)
N.I.N.A., DSS, APP, PixInsight, PS

Copyright: Massimo Di Fusco