Speed of gravity

By the formula it seems to be crystal clear that the force of gravity i.e Fg = GMm/r^2 well as we see there is absolutely no factor involving time and thence it has to be independent of, wrt time, so is it instantaneous? As mentioned in above post will the effect of sudden disappearance of sun will be instantaneous? Now if we decide as per the above formula of Fg then it seems that the loss of gravitational field around earth due to sun will be instantaneous that is earth will start traveling tangent to its rotational path at the instant the sun disappears but we will notice that this is happening only after 8.3 min no this is weird and quite contradictory as the physical effect on the world cannot exceed the speed of light that is if this at all happens then as per frame of reference at the position of the sun the earth will have velocity higher than the velocity of light....thus the speed of gravity in this case is infinite or higher than that of light.... this contradiction thus we can see is giving birth to therefore a different concept that the rate of disappearance of sun cannot exceed speed of light or it cannot be ,as considered in question, instantaneous.. that is the gravitational field cannot be added or withdrawn from a given area at a rate higher than the speed of light...thus the laws of relativity can be restated as, "In any conservative system, the ENERGY FIELD or POTENTIAL cannot vary at a rate higher than C."

Thus the speed of gravity has to be less than or equal to speed of light.