A pulsar is a rapidly rotating neutron star which emits a concentrated beam of electromagnetic energy. The name is an abbreviation of "pulsing star", because its intensity fluctuates in a regular cycle — only a couple of seconds or less — as the beam sweeps over the observer in the star's rotation.
When the first pulsar was observed on November 28, 1967, its regular pulse of energy suggested an artificial source. The astronomers who discovered the phenomenon nicknamed it "LGM-1", short for "Little Green Men". When a second such source was discovered, they realized it was more likely a natural phenomenon.
Some millisecond pulsars pulse at a rate more regular and reliable than an atomic clock, making them potentially useful for keeping time.
Game and Story Use
- In a space-based campaign, the players might encounter a pulsar
- A pulsar might be used in science fiction as both an energy source and a clock. "At the tone, your time will be 10:36:27.000."