The Lagrange equilibrium points L4 and L5 in black hole binary system

Abstract

We calculate the location and stability of the L4 and L 5 Lagrange equilibrium points in the circular restricted threebody problem as the binary system evolves via gravitational radiation losses. Relative to the purely Newtonian case, we find that the L4 equilibrium point moves toward the secondary mass and becomes slightly less stable, while the L5 point moves away from the secondary and gains in stability. We discuss a number of astrophysical applications of these results, in particular as a mechanism for producing electromagnetic counterparts to gravitational-wave signals. © 2010. The American Astronomical Society. All rights reserved.