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;