Hubble Galaxy Classification Chart - Types of Galaxies Explained #56583 (License: Personal Use)

This diagram illustrates Edwin Hubble’s iconic “tuning fork” galaxy classification system, categorizing galaxies into ellipticals (E0-E7), lenticulars (S0), normal spirals (Sa, Sb, Sc), barred spirals (SBa, SBb, SBc), and irregulars (Irr). Each type reflects structural differences in bulge size, disk prominence, and spiral arm tightness. The layout visually conveys evolutionary hypotheses, though modern understanding shows galaxy evolution is more complex than a linear sequence.

Used in astronomy education, textbooks, museum exhibits, and science websites to teach galaxy morphology; targets students, educators, amateur astronomers, and curious learners seeking foundational astrophysics knowledge.