We have a current value of

sun surface temperature =5778k

distance from sun to earth =1.5*10^8

perihelion distance =1.48*10^8

aphelion distance=1.53*10^8

solar constant on the top of earth =1400wm^-2

sun irradiance=6.30*10^7 wm^-2

sun radius =7*10^5 km

ellipticity=.017

the angle of polar=23.5 degree

question: calculate the earth radiative equilibrium temperature for the day (24hr) on perihelion (the planetary albedo is about 26%) and on aphelion (the planetary albedo is about 30%), and compare the mean solution to the current mean temp value and explain it.