No model has been presented for a unified theory of "celestial gravitation" because the reasons it would exist aren't observed. If one posits that they are a result of mass, then the magnitudes and distances don't add up (figuratively). It's impossible for extremely distant stars to have a macroscopic impact on Earth while Earth, the Moon, and the Sun have almost no impact. If the force increased with distance (like a spring), we should expect stars to fly over here at near the speed of light.
It's impossible to explain as one force that varies with distance:
1) The orbits of planets around their stars. (Moderate distances, large force)
2) Precession of a Foucault pendulum by the stars. (Extremely large distances, appreciable force)
3) Gravitational variations explained by the spinning of the Earth and different mass distributions in modern science (Small distances, appreciable force)
4) The forces binding the stars together
This is why I have concluded that FE introduces at least 3 new forms of gravitation. FE proponents would do well to stop talking about things abstractly and qualitatively, and start putting up some equations/laws about "celestial gravitation"; one then clearly sees that there are either many forms of it, or that perhaps Round Earth theory is not as complex as they make it out to be.