Assuming that you have the mass of the star prior to the ejection of non-core material, is there any relation that can be used to approximate the mass of the resulting left behind core which will later go on to become a white dwarf, neutron star, or other similar core object?
EDIT: I did attempt to find such a relation on my own, but only found unrelated relations or simply that the core exists. I was unable to locate on my own any relation between mass and core mass.