What is left over after stars collide? To help answer this question, astronomers have been studying the center of the most massive ball of stars in our Milky Way Galaxy. In the center of globular cluster Omega Centauri, stars are packed in 10,000 times more densely than near our Sun. Omega Centauri into individual stars. Visible are many faint yellow-white stars that are smaller than our Sun, several yellow-orange stars that are Red Giants, and an occasional blue star.