Precession Of Compact Binary Stars

A pulsar a highly magnetized, rotating neutron star that emits a beam ofelectromagnetic radiation.It is one of the four greatest discoveries of Astronomy. In1974,Joseph Hooton Taylor, Jr. and Russell Hulse discovered for the first time a pulsar in abinary system, PSR B1913+16. This pulsar orbits another neutron star with an orbitalperiod of just7.75hours. Einstein’s theory of general relativity predicts that this systemshould emit strong gravitational radiation, causing the orbit to continually contract as itloses orbital energy. Observations of the pulsar soon confirmed this prediction, providingthe first ever evidence of the existence of gravitational waves. But there are so manypulsars that we can’t explain the arriving time using our temporary theories and there aresome observations that there exists binary stars whose orbital period is increasing! Thiscontradicts with general relativity.According to the theory of general relativity, spin will cause energy-momentumtensors and have an effect on the orbit movement. So Damour used the effect ofSpin-Orbit Coupling to explain some problems of Astrophysics. But there are also someproblems which can’t be solved just using SO Coupling: In1998Wex gave a time modelof PSR B1259-63and the arriving time during7years. But in2004Wang Na used themodel of Wex to give the arriving time of PSR B1259-63during13years, and she foundthe observation was not consistant with the prediction of the theory.In our work, first we deduce the dynamical equation of the binary system withSpin-Spin Coupling, and compare this with the equation which ignore Spin-SpinCoupling.; then according to the method of post-newtonian approximation to generalrelativity which Damour has used, we conclude third post-newtonian accurate generalizedquasi-Keplerian parametrization for compact binaries; at the same time we add spin-orbitcoupling to third post-newtonian approximation; finally we use some approximation ofastrophysics to calculate the precession of the binary system which includes Spin-SpinCoupling.