For stars more massive than the Sun, the end is much more dramatic. Each time one type of the nuclear fuels is consumed, the core contracts a little further, the temperature rises and a new region is ignited. After a series of such steps with the star producing increasingly heavier elements the core is turned into iron. At this point the core can no longer support itself and it collapses violently with the outer layers of the star being torn apart in a supernova explosion.
The core continues to collapse to a neutron star which is only a few tens of kilometres wide but with its material so tightly packed that a teaspoon of it would have a mass of about a billion tonnes.
Life Cycle Menu Very Large Star Evolution