Fairly straightforward question/check of my understanding: It is my understanding that energy gravitates (is that proper phrasing?), but not potential energy, since that is energy of a system, not internal energy of an object. This would mean that as a star collapses and potential energy is converted to heat and pressure energy, its gravitational field measured from a distance would get stronger. Is that true? It seems to contradict what is typically said about black holes having exactly the same gravitational field strength at a distance after collapse as before - unless that's just a simplification due to the effect being small.