Wikipedia says:
The Lagrange points mark positions where the combined gravitational pull of the two large masses provides precisely the centripetal force required to orbit with them
The major bulk of the Solar System is concentrated in Sol with planets gravitationally bound to Sol. Sol orbits the galactic centre over a distance of some thousand light-years. The galactic centre is therefore massive enough to exert it's influence over such large separation.
- Can Lagrangian points exist for a whole planetary system/star-system? E.g. Between Sol, and the Galactic Hole. Similarly between any other Star in the galaxy, and the Galactic Hole.
- How much must a star/planetary system mass for such libration points to exist?