Trapezium Type Multiple Systems and Formation of Stars [chapter]

G. N. Salukvadze
1982 Astrophysics and Space Science Library  
By a comparison of Trapezium-type multiple star systems in the Abastumani Catalogue and the famous Catalogue of Stellar Associations and Clusters, it is confirmed that the great number of Trapezium-type multiple stars, which belong mostly to spectral classes 0-B2, are found in associations and clusters. In 13 T-associations, 120 Trapezium-type multiple systems and 182 common multiple and double stars could be detected. Based on present-day observational data and the author's photographic
more » ... photographic observations, the kinematic of Trapezium-type multiple stars of spectral class 0-B2 is studied. In studying the problems of stellar formation and evolution, special consideration is given to the investigation of unstable stellar groups and stars at non-stationary states. The unstable stellar systems in the galaxy are O-associations, Trapezium-type multiple systems and 0-type galactic stellar clusters. In stellar associations, Trapezium-type multiple systems are observed along with galactic stellar clusters. These are the multiple systems, in which, at any rate, three components can be distinguished. The distances between these components are of the same order. Prof. V.A. Ambartsumian regards the greater part of Trapezium-type multiple systems to have a positive energy. This means that such systems must expand. The calculations show that the expansion time is of the order of 2"10" years if the system has a negative energy and ~ 10 5 -10 6 years if it is positive. Therefore, in both cases Trapezium-type multiple systems are the youngest objects in associations (Ambartsumian, I960). The presence of a great number of Trapezium-type multiple systems in some stellar association or galactic cluster indicates that the 109 Z. Kopal and J. Rahe (eds.), Binary and Multiple Stars as Tracers of Stellar Evolution, 109-1 IS.
doi:10.1007/978-94-009-7861-4_13 fatcat:ypixtmql4nb7jovapuz34bbrum