Optical pulsars
Neutron stars
Radio pulsars
Pulsars
Rotation powered pulsars
Millisecond pulsars
Binary pulsars
A rotating neutron star that emits a radio beam that is centered on the magnetic axis of the neutron star. As the magnetic axis and hence the beam are inclined to the rotation axis, a pulse is seen every time the rotation brings the magnetic pole region of the neutron star into view. In this way the pulsar acts much as a light house does, sweeping a beam of radiation through space. The pulse or spin periods range from 1.4 milliseconds to 8.5 seconds. As neutron stars concentrate an average of 1.4 solar masses on a diameter of only 20 km, pulsars are exceedingly dense and compact, representing the densest matter in the observable Universe. The pulsar radiation, chiefly emitted in radio frequencies (0.1-1 GHz), is highly polarized. The exact mechanism by which a pulsar radiates is still a matter of vigorous investigation. Simply put, an enormous electric field is induced by the rotation of a magnetized neutron star. The force of this field exceeds gravity by ten to twelve orders of magnitudes. Charged particles are whereby pulled out from the stellar surface resulting in a dense, magnetized plasma that surrounds the pulsar (magnetosphere). The charged particles flow out of the magnetic polar caps of the neutron star, following the open magnetic field lines. The acceleration of the charged particles along the curved magnetic field lines will cause them to radiate.
Pulsar wind nebulae