Ch 10-01 From a Main Sequence Star to a Red Giant

• The zero-age main sequence (ZAMS)
  
  
  
  
• Evolution in and right after the main sequence
  
  
  
  
  [Shell hydrogen burning; the core contracts, outer layers expand.]
  
  
  [The red giant has a small core and loose atmosphere. Mass loss is severe, typically of 10^-7M_⊙/yr.]
  
  
  
  
• The main-sequence life time
  
  T ~ M/L ~ M^-2.5
  T ~ 10¹⁰ yr (M_⊙/M)^2.5