Question

The luminosity of the Sun is 4*10^{33} \, \mathrm{erg} \, \mathrm{s}^{-1}4∗10
33
ergs
−1
, and its radius is 7*10^{10} \, \mathrm{cm}7∗10
10
cm.

What is the Sun's effective temperature? Please enter your answer in units of Kelvin.

Answer 1

Answer:

1 Watt = 1 J/s = 10^7 erg/s

1GW = 10^9 J/s

the area of the sun is

4pi*(7*10^5 km)^2 = 6.2*10^12 km^2

So the solar output is

4*10^17 GW/6.2*10^12km^2

= 6.452*10^4 GW/km^2