# Calculate the rate of energy output of the sun, taking the sun as a blackbody

1. Aug 17, 2012

### ninaw21

1. The surface temperature of the sun is approximately 5800K. Given that the radius of the sun is 6.96x108m calculate the rate of energy output of the sun, taking the sun as a blackbody.

2. H = εσAT4

3. Surface temp = 5800K, Radius of the sun = 6.96x108, Emissivity of a blackbody = 1
H = εσAT4
H/A = (1)(6.96x108)(5800)4
= 7.87x1023W/M2

Am I right??

2. Aug 17, 2012

### lewando

No. Question is asking for "the rate of energy output" which is power (watts). You also seem to be confusing radius with σ, Stephan's constant.