Lagrangianpoint

La·gran·gi·an point (lə-grānʹjē-ən) n.

Astronomy. Any of five points, stable with respect to gravitational forces and in the orbital plane of two bodies, one of which is much larger than the other. A third, smaller body placed at one of these points will remain in equilibrium with respect to the other two bodies.

  [After Lagrange, Comte Joseph Louis.]

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