Question

ou recently read that a new possibly habitable planet was discovered. The planet, Burt, receives 2100 W/m2 from it’s companion star. If planet Burt has a a radius of 7500 km and acts like a blackbody ( emissivity =1 ) and thus radiates same amount of energy it absorbs, what is its average suraface temperature. For comparison the earth has a surface temperaure of 278 K.

I know you use the Pradiation equation
P=AesT^4
e=epsilon
s=sigma
T= temp in Kelvin