Unified Theory of Nature should possess ability to solve any secrets. So, the double, triple and more multiple star groups, in which stars move in unison, concerning the common centre, are known. There is variety of secrets of the multiple stars. For example, the secret of formation of the star group with various mass of stars, with  various colour. Why the stars in a group have various ratation rates? Whence there are the observed between stars in group the rigid and soft connections. Convincing explanations of origin of two, three and more multiple stars and singularities of behaviour of groups of stars (and stars in a group) are not available, and explanations happen apparently erroneous. In particular, in the up-to-date science it is considered that a double star is organised under the influence of the tidal forces (on E.Rosh) [20, page 235]. It for triple and more multiple stars almost improbably. Besides, from Unified Theory of  Nature it is followed (Gear of disruptures of bodies  and Lunar tides see) that the tidal forces, organising  double star, do not exist. Let's uncover the origin and singularities of behaviour of double, triple and more multiple groups of stars on the basis of Unified Theory of Nature.

A solution of secrets of the multiple stars. If one of the flows of ether, flowing   in the field (of the future star) with the before under density of ether, has retarded concerning the others more, than in the case indicated in Formation of galaxies and stars, then the others can already form an stable vortex. Then the delayed direct (unstable) flow, having come nearer to the condensed rotating (stable) field (Squeezing has generated the stability and  The vortex motion – the stable see), it is turned in the direction with the same name with the proximate cross to it flow, forming the second younger vortex (fig. 36). Then its sign of rotation appears the return in relation to the first.

                   Fig. 36. Phases of formation of second star in the future "double star". 

It is formed the "double star" with own rotation of its components – the single stars (the gyration concerning own axes) in the different ways and the gyration concerning the general centre towards the become by the first stable vortex, i.e. towards the senior vortex. By that, apparently, the masses of the stars necessarily will various. The ether motion to the two stars forms on the  removal from these 2 stars own ethereous macrovortex.

They are formed the three, four and more multiple stars similarly. At the greater  retardation of the subsequent flow of ether the stars with the greater difference in phase (so, the age) are formed.

For example, the first – the  white giant or the white dwarf, the second – the red dwarf; or: the first – the yellow of medial luminosity, the second – the  red giant. By that one of the stars can be «a black hole» (Black hole – the ether vortex see).

Two formed vortexes (in a "double star") begin the coexistence (the interaction) from the moment of the contact (fig. 36 a), leading to the joint motion of ether in the place of the contact of jets of the next vortexes. It leads to that the vortex 2 (fig. 36 δ,b) cannot keep away from the vortex 1 because of the ether flow, converging to the vortex 1. The vortex 2 cannot inflow in the vortex 1 also because of they rotate  every in the different way. The simulated conditions of the first vortex concerning the second also.  

As a result of these requirements in process of the interaction of the rotating vortexes the place of their mutual contact is biased on the periphery of each of the vortexes to the different sides towards own rotation. Two vortexes "roll" the friend on the friend, everyone having the itself trajectory concerning the general centre * (fig. 37).

 Fig. 37. Formation of a general centre of rotation of 2 stars: 1 –  the smaller vortex;

2 – the greater vortex; 1Ц – the centre  of the smaller vortex; 2 Ц – the centre  of the greater vortex; О Ц – the general centre of the system gyration. 

By that because of the elasticity of ether in the vortexes the system is inclined to the oscillations: the mutual removal-approach (the soft bond), that follows from the stability theory of systems [27]. These oscillations, depending on the requirements of the begun reprochement, can be the imperceptible (that is wrongly perceived as the presence between the stars of the rigid bond).

The rather major difference in the sizes of two ethereous vortexes lead to that the general centre of rotation coincides with the centre of the greater vortex. The smaller star is transmuted into the star – satellite of the greater.

At the insignificant difference of the sizes of two vortexes the general centre of rotation is in the middle between the stars and the stars describe one circle.

At the intermediate value of the difference of sizes of the vortexes the general centre of rotation of two stars is biased to the greater vortex and the greater star describes the smaller circle, and the smaller – the greater one. 

Quantity of double stars. It is known that in Universe there is a considerable quantity of double stars. Triple and more multiple it is essential less. Why it so? It is not known.

According to the Unified Тheory the collision probability of two jets of ether in "restless"  Universe (The ether fluxion see and "Formation of galaxies and stars" see above) is significant enough, that leads to formation of double stars (Look above). Probability of such meeting of three and more jets, according to the gear of formation of multiple stars on the Unified Тheory  is rather small.

Thus, the riddles, existing in the up-to-date science, are solved by Unified Theory of Nature.

   * The certain analogy from engineering – the "planetary" hitch of gear-wheels in the automobile differential.