Homographic solutions of the curved 3-body problem.

link: http://arxiv.org/abs/1001.1789
Abstract

In the 2-dimensional curved 3-body problem, we prove the existence of
Lagrangian and Eulerian homographic orbits, and provide their complete
classification in the case of equal masses. We also show that the only
non-homothetic hyperbolic Eulerian solutions are the hyperbolic Eulerian
relative equilibria, a result that proves their instability.