RCW 57 in Carina. The left and right halves are completey different in character. The left half, surrounding open cluster NGC 3603, is chaotic, with much black dust yet to be converted into stars. The right half, including NGC 3581 and many others, shows great billowing arcs of material, presumably subsequent to supernova explosions, and is presumably older.
H-alpha 19 hrs in 1 hr subs. Aspen CG16M on 20 inch PlaneWave. Three panel mosaic. Processed with our own GoodLook 64
