The Propeller Nebula

Image Description and Details : This cosmic landscape features a often overlooken object in the amateur astronomy community, Simeis 57. It’s nicknamed as the Propeller Nebula. I imaged this nebulosity on multiple nights during September and October between brief gaps in the clouds, acquiring a total exposure time of 14 hours with narrowband filters + RGB for the stars.

Most amateur astronomers use designation DWB 111 for the "Propeller" but it is incorrect as it is only a designation for the southern arm of the object. Designation DWB 119 is used for the northern arm. In 1950s Crimean Astrophysical Observatory at Simeiz, Ukraine designated this object as Simeis 57 in their catalogue of 306 objects of HII regions.
Ten years later the DWB catalog was created by H. R. Dickel, H. Wendker, and J. H. Bieritz. This catalog was intended for HII regions in the Cygnus X complex that they were studying in 1960s. Distance of this nebulosity is unknown but in general the objects in the Cygnus X complex are about 4600 light-years away.

Copyright: © Ville Puoskari