Pulsars

First published: 1997

Brief summary

NASA overview of pulsars as precise rotating periodic sources.

Article

Pulsars are rapidly rotating neutron stars that emit beams of electromagnetic radiation from regions associated with their magnetic poles. If a beam sweeps across Earth during each rotation, telescopes detect a regularly repeating pulse.

Neutron stars form when the cores of sufficiently massive stars collapse during supernova explosions. Conservation of angular momentum produces rapid rotation, while compression strengthens the magnetic field and concentrates emission into directed beams.

Pulse periods range from milliseconds to several seconds and can be measured with very high precision. Pulsars gradually lose rotational energy and usually slow over time, although sudden changes called glitches can interrupt the otherwise regular progression.

Precise pulse timing is used to study neutron-star interiors, binary motion, interstellar matter and gravitational physics. Networks of millisecond pulsars can also be compared over long intervals to search for correlated timing changes produced by very-low-frequency gravitational waves.

Source details and credits

• Source / publisher: NASA
• Source type: Educational article
• URL type: WWW
• Credits: NASA
• URL: https://imagine.gsfc.nasa.gov/science/objects/pulsars1.html