a degenerate neutron star; small and extremely dense; rotates very fast and emits regular pulses of polarized radiation
"Astronomers detected a distant pulsar rotating hundreds of times per second, sending out precise bursts of radio waves that act like a cosmic lighthouse."
A rotating neutron star that emits radio pulses periodically
"Astronomers detected a new pulsar in our galaxy and confirmed its rapid rotation by measuring the precise timing of its radio pulses."