The Double Pulsar J0737--3039: Testing the Neutron Star Equation of   State
  The double pulsar J0737--3039 has become an important astrophysical laboratory for testing fundamental physics. Here we demonstrate that the low measured mass of Pulsar B can be used to constrain the equation of state of neutron star matter {\em under the assumption} that it formed in an electron-capture supernova. We show that the observed orbital parameters as well as the likely evolutionary history of the system support such a hypothesis and discuss future refinements that will improve the constraints this test may provide. 
Ph. Podsiadlowski, J. D. M. Dewi, P. Lesaffre, J. C. Miller, W. G.   Newton, J. R. Stone