When combined with other data, the lightcurve of an eclipsing binary can be used to make measurements of the mass, temperature, size, and other characteristics of the individual stars in the system. Study the hypothetical lightcurve below. Suppose another astronomer has determined from independent spectroscopic observations that one of the stars is an identical twin of the Sun, that the stars are separated by 0.1 A.U, and that the first minimum (at 2 days) occurs when the Sun-like star is behind the other star.

  • What are the relative sizes of each star?
     
  • What are the masses of the individual stars?
     
  • Is the companion star hotter or cooler than the sun-like star? Provide justification for your answer.

HINT: You may find Kepler's Third Law helpful in answering some of these questions.

 

 

ecbin curve