Abstract

The Double Pulsar J0737 - 3039A/B, discovered with the Parkes radio telescope in 2003, is one of the most intriguing pulsar discoveries of the last decade. With its orbital velocity of ~1% of the speed of light, it is the most relativistic system ever found and, thanks to the presence of two active radio pulsars, it has also shown unprecedented mutual interactions between the radio beam of one pulsar and the magnetosphere of the other. Due to these characteristics, the Double Pulsar can be used for a wide variety of experiments, ranging from relativistic gravity, to plasma physics, and to pulsar electrodynamics. Moreover its discovery enhances –- by almost an order of magnitude – estimates of merger rates for double neutron stars systems, providing new possibilities for the current generation of ground-based gravitational wave detectors. In this paper we review the main observational properties of the Double Pulsar and their application for physical and astrophysical studies.