Nebular Diagnostics

• examples:
  I Zwicky 18: optical image, spectrum SN 1006: optical image, filament spectrum
• temperature diagnostics
• density diagnostics

Interstellar Dust

Evidence for Dust

• pioneering papers: Barnard (1907) (1910); Trumpler (1930)
• dark clouds: in Aquila, Carina; Barnard 68 here and here, 163; infrared views of HH 46/47, B68
• Milky Way lanes
• the Zone of Avoidance
• reflection nebulae