hello, you question is interesting, ..i think about it ...and if i understand: the teoritically understands ... the Total mass and the center of the mass it - can be absolutley the same mass and value...but the another question is, should this mass are static or with eclipse... ectually every mass on our Planet are in some procent full with eclips becouse our sun sistem all the time travel in the univerce... and more.. or few..the invisible energia cross all matter ...well we know that the sun sistem travel with definite speed in the universe ...and i think there are no static mass or "object"