Planetary nebula is a relatively short phase in the evolution of 95% of stars (including Sun), in which red giants become white dwarfs. These cosmic objects appear as small bright ring or disk shaped nebulae, sometimes hardly distinguishable from other stars. The first telescopic observations likened them to the discs of the planets of the Solar System, hence their name. Regardless of the clarified nature of these nebulae in the late XIX-th century the name is preserved. The remaining 5% of stars with mass greater than 8 times the mass of the Sun end their lives as supernovae. In the center of the planetary nebula is situated white dwarf that emits in the ultraviolet and the substance of the nebula converts this radiation in the visible spectrum. The temperature of the planetary nebulae reaches 10,000 to 20,000 K and density - thousands of atoms in 1 cm3. The degree of ionization is higher than in diffuse nebulae, falling from center to edge.