From the lab: Why spiral galaxies beat the ‘bulge’

GALAXIES ARE the fundamental building blocks of our visible universe, each containing billions of stars, like our Sun. They can broadly be classified into two types — elliptical and spiral. A typical spiral galaxy has two structural components: a central bulge in which stars move, more or less, on random orbits and a disk in which they move on approximately circular orbits like planets in our solar system.
Understanding the formation and the evolution of these galaxies over the age of the