The Cosmos with Simeis 57
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. … Bieritz in 1969, cataloging 193 distinct objects as part of their study of Hα-emission nebula in the Cygnus X region of the sky.