Video narration
Imagine a dead star, spinning so fast, it completes hundreds of rotations every second. This incredible object is called a pulsar. It's the collapsed core of a massive star that exploded in a supernova. Although only about the size of a city, a pulsar can contain more mass than our Sun. Some pulsars spin over 700 times every second, making them among the fastest-spinning objects in the universe. As they rotate, they release powerful beams of radiation. When those beams point toward Earth, astronomers detect regular pulses. A dead star. Extreme gravity. Hundreds of spins per second. Pulsars are nature's ultimate cosmic clocks.