On the association of Hickson compact groups with loose groups

Counts of galaxies are made in the vicinity of Hickson compact groups (HCGs ). Loose group galaxies are detected in similar to 70% of nearby groups wit h z < 0.025. It is shown that members of the loose group associated with a certain HCG are located in a relatively narrow strip oriented along the elo ngation of the HCG. Such a peculiar distribution of the loose group galaxie s and the found correlation of the radial velocity dispersion of the loose group galaxies with the elongation of the group allows us to conclude that the loose group galaxies are rotating around a common gravitational center. This is a clue for the solution of the known puzzles related to HCGs: the lack of strong radio and luminous far-infrared sources, a surprisingly larg e spiral fraction, the lack of blue elliptical galaxies, and so on. Only th ose of such elongated formations in which the bright members happen to be o riented close to each other on the sky are detected as compact groups.