prior to 2015 and the operation of advanced ligo, binary pulsars were the only tools scientists had to detect evidence of gravitational waves; einstein's theory of general relativity predicts that two neutron stars would emit gravitational waves as they orbit a common center of mass, which would carry away orbital energy and cause the two stars to draw closer together and shorten their orbital period. a 10-parameter model incorporating information about the pulsar timing, the keplerian orbits and three post-keplerian corrections (the rate of periastron advance, a factor for gravitational redshift and time dilation, and a rate of change of the orbital period from gravitational radiation emission) is sufficient to completely model the binary pulsar timing.