The Highly Relativistic Binary Pulsar PSR J0737-3039A: Discovery and   Implications
  PSR J0737-3039A is a millisecond pulsar with a spin period of 22.7 ms included in a double-neutron star system with an orbital period of 2.4 hrs. Its companion has also been detected as a radio pulsar, making this binary the first known double-pulsar system. Its discovery has important implications for relativistic gravity tests, gravitational wave detection and plasma physics. Here we will shortly describe the discovery of the first pulsar in this unique system and present the first results obtained by follow-up studies. 
M. Burgay, N. D'Amico, A. Possenti, R.N. Manchester, A.G. Lyne, B.C.   Joshi, M.A. McLaughlin, M. Kramer, J.M. Sarkissian, F...