•Q1. The
“Blade Runner Question.”
A star that burns half
the lifetime of the sun does not burn twice as bright.
How bright (luminous) is it?
• Lifetime in solar units = M-2.5 (solar m)
• 0.5 =
M-2.5
• M2.5 = 2
• M =
(2)1/2.5 = 20.4= 1.3 solar masses
• L in
solar units = M3.5 (solar units)
• Luminosity
= (1.3)3.5 = 2.6 solar