On Relativistic Astrophysics.

In this paper we have attempted to discuss the relation of massive highly condensed objects to astrolysics in general, rather than only to the radio-source problem. Because situations in which general lativistic effects play a dominant role have not received much attention in astrophysics, a brief review the relativistic properties of collapsed objects is in Section I of the paper. In Section II we have given especial attention problems: (1) Galaxies may contain considerable iantities of inert or "hidden" mass, not simply in the form of white dwarfs or neutron stars (2) Highly llapsed objects may act as energy sources, not just explosively, but over extended time intervals. The first of these problems has implications both for nucleosynthesis and for the mass-to-light propties of stellar systems. The second appears applicable to a wide range of phenomena, ranging from supervae in our Galaxy to whole radio galaxies. A continuous source of optical synchrotron electrons appears cessary both in the Crab Nebula and in the jet of M87. We suggest their origin lies in processes that e physically similar and in which considerations of general relativity play a dominant role.