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  8. Possible variants of beginnings of synthesis generation, nuclear kernels, in «the accretion disk» in moment of birth of Star

  In this section, we shall consider some possible variants, the succession of events, during the beginning of thermonuclear synthesis in «the accretion disk».

«The accretion disk» appears in cases of «the white dwarf», «a neutron star» and «a black hole». Other variants of occurrence of «the accretion disk» are possible at the turbulence of gas streams. An example of turbulences in gas streams, probably, is the star-formation in the disks and the sleeves of galaxies. Other variants are possible as well. In this section, we do not consider the probability and the conditions of the beginning of thermonuclear synthesis in «the accretion disk». Proceeding from the research data — this fact exists. We shall consider some possible variants of events succession at the beginning of thermonuclear synthesis in «the accretion disk» and some processes influencing the formation of stars. In figure №R-8.1 is represented the scheme of «the accretion disk».

                                                                    (136) Figure №R-8.1

Zone «A» — internal vacuum area in the center of «the accretion disk», in cases of «the white dwarf» or «a neutron star», in zone «A» there are «the white dwarf» or «a neutron star».

Zone «B» — a gas stream, moving in circulation.

Zone «C» — external area. The area of space adjoining to the external borders of «the accretion disk».

In the given section we are interested in the processes of star-formation in «the accretion disks» of different sizes.

Let’s consider the variants of the beginning of thermonuclear synthesis in «the accretion disk», and a possible, succession of events.

                                            Variant 1

The thermonuclear synthesis begins in a zone «B» at the border with zone «A», figure №R-8.2

68-1-137-En str 68-1

                                                     (137) Figure №R-8.2

In this case the development of thermonuclear synthesis goes from the center to the periphery in the direction from zone «A» to zone «C».

The development of events will probably occur in several ways.

   — The centers of thermonuclear synthesis rise to the border between zones «B» — «C», and are distributed all over the external border of «the accretion disk». In this case, the area of thermonuclear synthesis will pass (will rise) to the border between zones «B» and «C» - figure№R-8.3.

68-2-138-En str 68-2

                                                                (138) Figure №R-8.3

Under the action of dynamic pressure directed from zone «D» to zone «A», the gas of zone «B» will be compressed. Under the action of the same dynamic pressure in zone «B» — new centers of thermonuclear synthesis which will rise in zone «D», supporting its existence should be formed. «The accretion disk» passes into the state of a young star. The zone «A», under the action of dynamic processes, will probably disappear. Dynamic shock waves going from zone «D» to zone «A» are concentrated and accumulated in the center of «the accretion disk», destroying zone «A». A generation of thermonuclear synthesis along the line of shock waves is possible. Having gathered and collided with each other in the center, they will be reflected in an underside, in the direction to zone «D» («C»). This reflected wave will meet the following shock wave going from zone «D» to the center. In zone «B», at the meeting of these two shock waves there should be a zone of thermonuclear synthesis — «E», figure №R-8.4.           

68-3-139-En str 68-3

                                          (139) Figure №R-8.4       

This possible case is characteristic for «the accretion disks», whose weights are commensurable with weights of stars.

In case of greater weights, the succession of events, probably, leads to the break of «the accretion disk» and to a birth of more than one star.

 The break of «the accretion disk» is possible in the following cases:

  — In an uncontrollable development (increase) in the thermonuclear synthesis;