Remark on Ambartsunian's protostars

Ambartsumian's theory of stellar evolution states decay and expansion of protostellar matter which formed 'protostars'. Such objects were assumed to be a very extraordinary form of matter and cannot be fitted into the frame of usual relativistic astrophysics. The present paper shows that anticollapsing bodies, 'white holes', in which gravitational collapse happens with opposite time direction, offer a natural explanation for the physical nature of protostars. (D.Gy.)