Astronomers also have noticed that as they examine the images of these
distant blue galaxies, the images are frequently distorted or contain
what appear to be multiple nuclei. The Milky Way seen at a similar
great distance would look like a uniformed flattened disk, with a
single bright nucleus -- the galactic center. Nearby
"multiple-nuclei" galaxies that have been studied show the cores of
individual galaxies colliding and merging into one single system of
stars and gas. These collisions are violent, and take millions of
years to play out. But in at least some instances, such as NGC 1275,
recently observed with the Hubble Space Telescope, galaxy collisions
can actually
trigger the formation of massive stars.