3
Lifetime on Main Sequence
•L µ M3.5 T µ fuel / L = M/M3.5 = M-2.5
•Example:  M=2 MSun      L = 11.3 LSun        T =1/5.7  TSun
•
•
  56 ´ 109
           0.08
   0.5
M0
  17 ´ 109
           0.46
   0.8
K0
    8 ´ 109
           1.4
   1.1
G0
    3 ´ 109
           6.1
   1.7
F0
440 ´ 106
         80
   3.5
A0
  11 ´ 106
  13,000
 15
B0
    1 ´ 106
405,000
 40
O5
Years on Main Sequence
Luminosity
(Sun = 1)
Mass
(Sun = 1)
Spectral
Type