Unique characteristics of the Crab Pulsar:
For a Hubble Space Telescope movie of the Crab Nebula, click
Here.
A diagram explaining the movie is given Here
The Supernova which created the Crab Nebula (and the Crab Pulsar) was
observed in 1054 A.D. by Chinese Astronomers. These superb records
enable us to carefully measure the evolution of this Supernova with time.