Аннотация:The history of the introduction and development of the star complexes conception is
briefly described. These large groups of stars were picked out and named as such ones in
our Galaxy with argumentation and evidence for their physical unity (using the Cepheid
variables the distances and ages of which are easy determined from their periods);
anyway earlier the complexes were noted along the spiral arms of the Andromeda
galaxy, but were not recognized as a new kind of star group. The chains of complexes
along the spiral arms are observed quite rarely; their origin is explained by magneto-
gravitational or purely gravitational instability developing along the arm. It is not
clear why these chains are quite a rare phenomenon – and more so why sometimes
the regular chain of complexes are observed in one arm only. Probably intergalactic
magnetic field participated in formation of such chains. Apart from the complexes
located along the arms, there are isolated giant complexes known (up to 700 pc in
diameter) which look like super-gigantic but rather rarefied globular clusters. Until
now only two of these formations are studied, in NGC 6946 and M51.