# Eclipsing binary stars question

1. Feb 22, 2010

### warfreak131

1. The problem statement, all variables and given/known data

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. Fnormal is the flux from the system when neither star is blocked. and fa and fb are the fluxes when star 2 passes in front of, or behind star 1, as seen from Earth.

(A)Compute fa/fnormal
(B)Compute fb/fnormal

The light curve looks like this:

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

where the top line is fnormal, the drop at x=.5 is fa, and the drop at x=1 is fb.

2. Relevant equations

Flux = $${\sigma}T^{4}$$
Brightness = $${\pi}R^{2}{\sigma}T^{4}$$

3. The attempt at a solution

I am being thrown off because the question says compare the fluxes, but just computing the flux doesnt 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.

Last edited: Feb 22, 2010
2. Feb 23, 2010

### warfreak131

sorry, i didnt post this in the astronomy section