The Propeller Nebula (Simeis 57) is part of a vast and rich HII-region in Cygnus, known as Cygnus X Complex. The Propeller Nebula is located close to Gamma Cygni in the direction of north-east. 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 Propeller Nebula is probably about 5,500 light-years away from Earth.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 c...