Galaxy Properties

• Gravitationally bound:

  • 200-400 billion stars
  • DISK components and SPHERE components

• DISK:

  • Confined to plane of rotation
  • Stars, open clusters, gas, dust
  • Most star formation here => young, hot, blue luminous stars
  • We’re ~ 8.5 kpc from center
  • Luminous radius ~ 12.5-15 kpc

Notes: