NGC 1850. While part of this may well be the remnant of the 'parent' gas cloud (i.e. the one from which both clusters were born), the presence of filaments and of various sharp 'shocks', e.g. to the left and below NGC 1850, offers support to the theory of supernova-induced star birth in the younger of the two clusters. Some 'protostars' are located near or in some of the filaments - this is interpreted as additional evidence for that theory. The nebulosity directly above the main cluster, that is shaped like a '3', is the well-known supernova remnant N57D which itself may also be associated with NGC 1850.