DWB 111/119, also known as the Propeller Nebula is a hydrogen-alpha emission nebula in Cygnus. The propeller shape is actually a small portion of a much larger emission nebula, which can be seen as faint red hydrogen-alpha nebulosity throughout the image frame. The distance to the nebula is not known.The Propeller Nebula is part of a vast and rich region in Cygnus known as Cygnus X Complex. The Propeller itself is most often designated as DWB 111; however, the proper designation is Simeiz 57.

The Simeiz Catalog was created in the 1950s by the Crimean Astrophysical Observatory at Simeiz, 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 really only deals with the southern arm of the Propeller, while DWB 119 deals with the northern arm.

The Propeller Nebula is located close to Gamma Cygni in the direction of north-east. Like many emission nebulae in Cygnus, the Propeller is part of the giant molecular cloud, the Cygnus X, which is about 4600 light-years apart from the Solar System. There is another, much more closer dark molecular cloud between it and us, in a distance of about 300 light-years, called the Cygnus Rift, which makes its observation much more difficult. Cygnus Rift can be observed by the naked eye under dark skies: it is the dark strip dividing the Milky Way into two parts, spanning from Cygnus to Sagittarius. The enormous quantity of dust and plasma contained by Cygnus Rift absorbs the most of the light coming from stars and other objects behind it.Unfortunately we know quite little about the Propeller Nebula, even its distance is undetermined yet. It mostly emits at the line of hydrogen-alpha, while it is much dimmer on other wavelengths. The stars or other sources responsible for the ionisation of the gas is also still to be identified. The mass of the cloud is less than 50 Solar masses, according to estimations.