Eclipsing binary stars question

[warfreak131]

Homework Statement

Figure 1 showed the light curve for an exlipsing binary system. This system consists of 2 stars. Star is is the larrger of the stars, and has a surface temp of T₁=5000 K. Star 2 has a surface temp of T₂=10000K. The ratio of their radii is R₁/R₂=4. F_normal is the flux from the system when neither star is blocked. and f_a and f_b are the fluxes when star 2 passes in front of, or behind star 1, as seen from Earth.

(A)Compute f_a/f_normal
(B)Compute f_b/f_normal

The light curve looks like this:

http://www.ifa.hawaii.edu/users/mendez/ASTRO110LAB07/modeleb.gif

where the top line is f_normal, the drop at x=.5 is f_a, and the drop at x=1 is f_b.

Homework Equations

Flux = [tex]{\sigma}T^{4}[/tex]
Brightness = [tex]{\pi}R^{2}{\sigma}T^{4}[/tex]

The Attempt at a Solution

I am being thrown off because the question says compare the fluxes, but just computing the flux doesn't take into account the fact that you are blocking out some light from each star when one passes in front of another. For that I would use brightness, but he makes no mention of using brightness in the question.

 

[warfreak131]

sorry, i didnt post this in the astronomy section