ON THE ORIGIN OF THE INTERSTELLAR DIAMOND S, SILICIC CARBIDE AND GRAPHITE IN CHONDRITES

A model of the interstellar relic formation in chondrites is presented based on the data on the properties and isotopic anomalies of element s of the interstellar grains of diamonds, silicic carbide and graphite is presented. The interpretation of the theoretical and experimental data in respect of the nucleosynthesis is also applied. According to o ur model the grains of SiC and graphite are assumed oto condense withi n the ring shaped nebula. The latter is considered to be formed of the O, B-star substance ejected at the initial stage of He burning in its core and transformed by intensive stellar wind. The local mixing of t he ejected matter and the stellar wind emitted at the different evolut ionary stages was resulted in great diversity of the chemical and isot opic composition of SiC and graphite grains. The low pressure area beh ind the front of the impact wave wave generated by the Supernovae form ed during the evolution of the massive O, B-second generation star is assumed as the most probable astrophysical object of the diamond forma tion. The diamond condensation from carbon atoms was presumably confin ed to a mixed layer of He and H shells in the high rate nonequilibrium process. The nuclear reactions proceeded during the condensation of d iamond, SiC and graphitic grains in the O, B-star resulted in the isot opic anomalies revealed are presented.