The unique binary pulsar system PSR B1259-63, comprising a radio pulsar in an eccentric orbit about a hot, massive companion star, has been extensively monitored at frequencies from the radio bands to hard gamma rays (TeV). The pulsed radio emission disappears for around 35 days around periastron. Unpulsed radio emission is detected for about 100 days around periastron, varying on time scales as short as a day. X-rays are detected throughout the orbit, with the intensity varying by a factor of a few. The pulsar is bathed in a huge density of UV photons from its Be-star companion, particularly around periastron. Inverse Compton scattering of these photons by relativistic electrons and positrons in the pulsar wind transfers some of the pulsar's rotational energy to hard gamma-ray photons, which may have energies as high as a TeV and should be detectable.

I will discuss the unique properties of this system, concentrating on the unpulsed radio emission and the inverse Compton scattering.