Calculate the radiation output of the following objects (use the Stefan-Boltzmann law).
a. Our Sun (surface temperature is 6000K)
b. Spica (a star in the constellation Virgo with a surface temperature of 18,000K).
c. The Earth (with an average surface temperature of 59°F)
d. A human body (with an average temperature of 98.6°F)
e. Pluto (a dwarf planet with an average temperature of 44K)