The system PSR J0737-3039 is the only binary pulsar known to consist of two radio pulsars ( PSR J0737-3039 A and PSR J0737-3039 B ) .
This unique configuration allows measurements of spin orientation for both pulsars : pulsar A ’ s spin is tilted from the orbital angular momentum by no more than 14 degrees at 95 % confidence ; pulsar B ’ s by 130 \pm 1 degrees at 99.7 % confidence .
This spin-spin misalignment requires that the origin of most of B ’ s present-day spin is connected to the supernova that formed pulsar B .
Under the simplified assumption of a single , instantaneous kick during the supernova , the spin could be thought of as originating from the off-center nature of the kick , causing pulsar B to tumble to its misaligned state .
With this assumption , and using current constraints on the kick magnitude , we find that pulsar B ’ s instantaneous kick must have been displaced from the center of mass of the exploding star by at least 1 km and probably 5–10 km .
Regardless of the details of the kick mechanism and the process that produced pulsar B ’ s current spin , the measured spin-spin misalignment in the double pulsar system provides an empirical , direct constraint on the angular momentum production in this supernova .
This constraint can be used to guide core-collapse simulations and the quest for understanding the spins and kicks of compact objects .