As the name suggestions, millisecond pulsars have pulse periods that are in the range from one to ten milliseconds. Most such millisecond pulsars are found in binary systems, typically with white-dwarf companions. These pulsars are highly magnetized, old neutron stars in binary systems which have been spun up to high rotational frequencies by accumulating mass and angular momentum from a companion star. Neutron stars form when a massive star explodes at the end of its life and leaves behind a super-dense, spinning ball of neutrons. A pulsar is the same thing as a neutron star, but with one added feature. Pulsars emit lighthouse-like beams of x-ray and radio waves that rapidly sweep through space as the object spins on its axis. Most pulsars rotate just a few times per second, but some spin hundreds of times faster. These millisecond pulsars are the fastest-rotating stars we know of.
- To hear the sound of a pulsar, click here