System space

Classes of material systems:

1. Meteor associations,
2. Satellite systems,
3. Planetary structures, i.e. meteors, moons and stars surrounded by a family of planets.
4. DOUBLE AND MULTIPLE STARS: I. Close systems: a) eclipsing, b) spectroscopic. II. Visual systems: a) gravitational P) optical. III. Pairs and groups of stars with a common motion;