Solution to Exercise 2

1. The nature of the dips in the light curve depend on whether the eclipses are partial or total and the relative sizes of the stars. If one star is smaller than the other and the eclipses are total we expect flat bottoms in the light curves. See the adjacent image for an example.

2. Eclipsing binaries only occur if the geometry is right to cause the stars to pass in front of each other as viewed from Earth. Eclipsing binaries are usually spectroscopic binaries because the orbital motion causes shifts of the spectral lines, but most spectroscopic binaries are not eclipsing as viewed from the Earth because the geometry isn't right to cause eclipses.