Galaxy Formation and Evolution/TalkAlmost all galaxies have an extrememly large black hole at their center, or many tightly-packed neutron stars formed from collapsing supernovas? over billions of years. All of the stars in the galaxy rotate around this massive center.
It has been suggested that the universe will end with neutrons as well, when all stars have collapsed into neutron stars and planets have been pulled into black holes. However, this may not happen for many billions of years.