A star having radius R has a small planet revolving around it at a distance d `(gtgt R)`. The star and the planet both behave like black bodies and radiate maximum amount of energy at wavelength `lambda_(s)` and `lambda_(p)` respectively.
(i) Find d in terms of other given parameters.
(ii) Show that `lambda_(p)gtgtlambda_(s) `

Answer

(i) `d=(R)/(2)((lambda_(p))/(lambda_(s))^(2)`