The energy and the angular momentum radiated away in the form of gravitational waves from a system of two point particles with positive total energy are calculated in the lowest nonvanishing post-Newtonian approximation. By these radiations a particle arriving from infinity can be captured, and the cross section for such captures is determined as a function of the energy at infinity. The radiation from elliptic (bound) orbits can also be inferred, and is found to be in agreement with known results.

• Received 18 August 1971

DOI:https://doi.org/10.1103/PhysRevD.5.1021