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#### zaf

##### Guest

I need help on a homework problem that I am unable to solve. the problem is as follows

Given the radius of a star of 9.0 * 10^3 m and surface temperature of

10000 k (blackbody)find the intensity of radiation (watts/m^2) incident on a planet that is located 2.4 * 10^11 m from the star

I found the total power radiated from the star by using stefans and taking the area to be 4 pi r^2 so P = sAeT^4

s is the stefan-boltzman constant

and e is emissivity of 1 for a blackbody

then I could also find the brightness for that star as seen from another planet 2.4*10^11 m away from the star by using

b = P / (4*pi*d^2)

d being the distance...but i do'nt think that this is the answer

can someone help ?