The Death of Stars

Stars produce their heat by using Hydrogen as a fuel for nuclear fusion.

This heat stops the star shrinking and collapsing because of gravity.

When that fuel runs out, the star will "die", but what does that actually mean? You can follow the story of the "death" of a star below.

	A star, seen from a planet like the Earth.

	The Hydrogen nuclear fuel in the centre of the star runs out. The outside of the star grows and cools, turning redder.

	After a while, the star is big enough to swallow up the planet completely! It is now a Red Giant (quite cool and red for a star, but very big!). Meanwhile, the centre of the star has been shrinking because of gravity and getting hotter.

	Eventually, in the very centre of the star, it will get hot enough for a new type of nuclear fusion to start, this time using Helium as the fuel rather than Hydrogen. It is then much more like a normal star again, and the Red Giant "outside" will shrink back.

	... a Red Giant. This is the Second Red Giant Phase. This will only last a million years or so.

What happens after this depends upon how much mass the star had to start with. Do you want to know what happens to A star like the Sun? A much bigger star? In both cases, material from the star, which includes hydrogen, helium and other heavier elements created through nuclear fusion in its core, can be ejected into nearby nebula to become building blocks for future generations of stars, planets and even life. It may seem strange, but the atoms and molecules of which we are made were created in the centre of stars that expired long ago. In a sense we are all made of Stardust.