How do Sa type galaxies differ from Sc types in the Hubble classification?
Sa types have tightly wound spirals and larger bulges
The Hubble classification system organizes spiral galaxies based on two primary visual characteristics: the tightness of their spiral patterns and the relative size of their central bulge. Galaxies categorized as Sa are characterized by having very tightly wound spiral arms that coil closely around a prominent, large central bulge. Conversely, galaxies classified as Sc exhibit loosely wound, more open spiral arms, and they typically possess a smaller central bulge relative to the overall size of the disk. This classification system provides astronomers with a quick visual metric to gauge the galaxy's morphology, which often correlates with star formation characteristics and gas distribution.
