Pulsars

Pulsars are highly magnetized, rapidly rotating neutron stars that send out regular pulses of radiation. They form when a massive star reaches the end of its life and collapses after a supernova explosion.

During this process, the star’s core becomes extremely dense, creating a neutron star that can contain more mass than the Sun while being only about the size of a city. As a pulsar rotates, beams of radiation from its magnetic poles can sweep across space like the light from a lighthouse.

The first pulsar was discovered in 1967 by astronomers Jocelyn Bell Burnell and Antony Hewish. Its regular signals were so unusual that they were initially called “LGM” for “Little Green Men” as a joke, before scientists understood their true origin.

Pulsars act as extremely precise natural clocks because their pulses can be measured with great accuracy. They help researchers study extreme physics, test theories of gravity, explore the structure of the Milky Way, and detect phenomena such as gravitational waves.