Some remarks on the general relativistic 2-body problem.

The effects of the gravitational self-field of a body on its motion are considered. No information concerning such effects has yet been provided within Einstein's theory of General Relativity. The discovery of the binary pulsar PSR 1913+16 and of other close binary systems, where neutron stars or black holes can be observed in fine details of their orbital motion, indicates that these problems are of astrophysical relevance, too. The general relativistic 2-body problem is considered along with the static 2-body problem. A calculation is conducted of the forces between the two bodies. It is found that the Schwarzschild mass of the isolated bodies is a reasonable quantity for multipole expansions, even in the full 2-body problem.