Our actions enable us experience the world and to know something about it. Discoveries made by sensor spacecraft telescopes start give us a comprehension of the universe that we can develop through more refined experiments with up to date detectors.
The universe we find is the result of our actions. It is the truth for us with the procedures and equipment available. To find out more about the dynamic masses of local group galaxies we have to use the Hubble and James Webb telescopes to further investigate the energies of stars in the outer regions of the discs.
It may be that the masses of stars vary with the energies coming together to make them. A varying mass function in modified Newtonian dynamics could enable us to comprehend the behaviour of galaxies clusters from experience gained with up to date sensor telescopes research.