The textbook discusses models of multi-particle systems of various scales: atomic nuclei, atoms, planets and stars, based on the application of the laws and methods of statistical physics and thermodynamics. The development of theoretical models of quasi-equilibrium states of such systems is shown - from the simplest to quite complex, close to real objects. The former give mainly a qualitative picture of the properties of objects and pursue didactic goals, the latter allow them to be studied quantitatively and set research tasks.