Understanding Spiral Galaxies: Structure, Classification, and Characteristics

Spiral galaxies are magnificent cosmic structures characterized by their pinwheel-like appearance, with a central bulge and distinctive spiral arms. These arms are indicators of rotation and contain both young and old stars, along with gas and dust. Approximately 80% of large galaxies are classified as spirals or barred spirals. Their classification depends on the number of arms and the tightness of their structure, ranging from S0 (without distinguishable arms) to Sa, Sb, Sc, and Sd (with increasing arm prominence). Explore the beauty and complexity of these galaxies.