You don't learn about ocean waves by staring at a snapshot. By their nature waves on the ocean are ever changing. You learn about ocean waves by sitting on the beach and watching as they roll ashore. This Hubble 'movie' of the Crab is so significant because for the first time we are watching as these 'waves' from the Crab come rolling in. Of interest here is the thermal evolution of the stars.
Different theories predict different temperature ranges for such stars.
If a star has about 10 times the Sun's mass, the extra internal pressure burns nuclear ash into heavier elements until it fuses silicon into iron and nickel. Such a supernova created the Crab Nebula. Links to 1280x1024, 427KB JPG . Besides the interstellar debris, supernova explosions often leave behind a cinder, a dense, collapsed core created by the compression of electrons and protons. The star's gravitational field is about 300,000 times stronger than the Earth's.