This is about the same as the mass ratio of the earth to the sun. The semi major axis a of the earth’s orbit is 1.0 AU, which is 1.496 ten power 11 metres. This is much smaller than a of S2, which is 1.4253 ten power 14 metres. So S2 is much further away from M, and we would expect weak gravitation at such distances between m and M. Strong gravitation is a type of higher order correction. I cannot see how it could possibly account for a discrepancy of a factor of ten million. It looks to me to be another total disaster for the Einstein theory. The orbit of S2 is an ellipse of high eccentricity, like a comet in the solar system. This observed ellipse shows conclusively that the S2 star is almost Newtonian, so relativistic corrections are very small. Similarly in the Hulse Taylor pulsar, I cannot see how a theory whose geometry is totally wrong can work at all. Maybe Stephen Crothers has some comments on strong gravitation and under what conditions it begins to make itself felt. Of course Steve rejects black holes as a fantasy, and so does the entire ECE2 school of physics.