AMBARTSUMIAN 16 



simultaneous origin on the stars in the Galaxy. This work pro- 

 vided a foundation for research in astronomy into the evolution 

 of stars and stellar systems by observation of their develop- 

 ment. The theoretical prediction (in 1947-49) by Ambartsumian 

 concerning the dynamic instability of stellar associations and 

 their expansion was confirmed as a result of the analysis of 

 movements of stars carried out in Leyden and Byurakan. 



Ambartsumian' s finding of the group character of the 

 emergence of stars has permitted clearer study of the physical 

 nature and cosmogonic role of double and multiple stars, star 

 chains and clusters, and gaseous nebulae. It has also resulted 

 in work by Ambartsumian on continuous emission, another as- 

 pect of the physical nature of the members of stellar associ- 

 ations. Continuous emission is the excess radiation in a total 

 spectrum observed in stars of the T Tauri and UV Ceti type and 

 also in comet-like nebulae. By synthesis and analysis of unco- 

 ordinated data, Ambartsumian established the non-thermal 

 character of continuous emission. This aroused great interest 

 in the origin of this entirely new phenomenon. At the present 

 time, extensive study of continuous emission is under way both 

 at the Byurakan Observatory and at a number of foreign ob- 

 servatories (Lick, Tonantzintla). 



In recent years, Ambartsumian began research on the 

 galaxies and on the systems constituted by them. One result of 

 his work is the conclusion (based on the group character of the 

 formation of galaxies) that galaxies form as multiple systems 

 and clusters having in many cases positive energy, that is, 

 constituting systems under disintegration. He interprets radio- 

 galaxies as the result of a process of division—the formation of 

 galaxies counterbalancing the hypothesis of collision of galaxies. 

 The blue galaxies detected by him, a particular kind of dwarf 

 galaxies, enrich our conceptions of the nature of galaxies and 

 may furnish much valuable material for studying the evolution 

 of galaxies. The very important role of nuclei of galaxies in 

 their evolution was shown. In particular it was concluded that 

 the nuclei of galaxies display a number of forms of cosmogonic 

 activity. 



In 1960 the composition of degenerate gas with nuclear densi- 

 ty and greater was studied. It was shown that with increasing 

 density, different hyperons successively appear and their 

 number in the gas increases. They should be stable due to the 

 Pauli principle. 



Then it is proved that in the case of the degenerate super- 

 dense gas the configuration of gravitational equilibrium of 



