4. The surface temperature of our sun is about 5800 K.
a.) Using Wien’s law (eq. 3-5) what is Ιmax (in nm) in the energy distribution curve of our sun?
b.) The color of the wavelength from part a.) is cyan, a blue green. The energy distribution function u(Ι)=[8πhcΙ⁻⁵]⁄[exp(hc⁄ΙkT) – 1] gives the intensity vs wavelength of a blackbody, e. g. a star, as plotted in Fig. 3-6. k=8.617 10⁻⁵ eV/K. Using this energy distribution function, what fraction of the sun’s emitted intensity at its peak wavelength (answer to a.) is emitted at the red color wavelength of 700 nm (i. e. how much dimmer is the red light emitted by the sun than the peak blue-green)?