A galaxy is a large collection of stars, often arranged into spiral arms in spiral galaxies, though elliptical, irregular, and lenticular galaxies have no spiral arm structure and instead are made directly of stellar belts.
The total number of stars in a galaxy ranges from 100 trillion for giant elliptical galaxies to just 1000 in the tiniest dwarf galaxies. The Milky Way, the type spiral galaxy, has 300 billion stars.
|E · S0 · Sa · Sb · Sc · Sd · Sm · Irr |
dSph · dE · dIrr