RCW 106 is a large star-forming nebula in the Constellation Norma. [1] RCW 106 is visible in the direction of the R103 OB association and is embedded in a 100 thousand solar mass 28 pc x 94 pc giant molecular cloud. The RCW catalogue designates the two brightest regions of this nebula as RCW 106a[2] and RCW 106b[3] but these do not appear to be distinct objects.[4]