Destruction of Open Star Clusters and the Radius–Mass Relationship

The processes of formation and six mechanisms of disintegration of open star clusters (OSCs) are considered. Analytical estimates of the rates of OSC disintegration are made for the following mechanisms: loss of the initial gas component of OSCs, mass loss due to supernovae explosions and planetary nebula formation, pair interactions of OSC stars, acceleration of stars by binary systems of OSCs, interaction of OSC stars with stars of the Galactic disk, collisions of OSCs with giant molecular clouds (GMCs) at the front of a spiral wave. The destruction of OSCs is accompanied by the formation of a stellar stream. An analysis of the radius–mass ratio of the OSC core (RM) allowed us to conclude that it probably does not reflect the disintegration mechanism and is a product of observational selection effects. The evolution of an individual OSC in the R–M plane is determined by the initial density and external conditions.