ShareUniverse Development - How Are Stars Related?
Supernovas are only one way that stars die and only certain stars are able to undergo a supernova. Remember the process that goes on inside a star? As the atoms fuse together, eventually the heavier elemnts such as iron are formed and the core of the star is iron. By then, the iron atoms are so massive that their force or repulsion is too strong to be pushed together to form other elements. What happens after that depends on the star's mass.
Stars, like humans, have a life cycle. Think about all of the events that occur in a human's lifetime. Now, we will discuss how a star goes through its life cycle. We'll first start with an average mass star such as our sun.
This is what can be expected from our sun. All stars, including our own, are born in a nebula from compressed gas and dust as hydrogen begins to fuse to helium. In a few billion years, our sun will have fused all of its hydrogen into helium. The helium will have been fused into carbon, and the sun will begin to expand until it has reached Red Giant proportions. At this time, much of the material will be vented off into space, forming a planetary nebula and all that will remain is the core, which is primarily carbon with some other elements, the heaviest probably being iron. That core will become a White Dwarf. Eventually, all fusion will cease and the final remains of our sun will be a Black Dwarf.
However, a star that is 1.5 to 3 times more massive than our sun has a much different life cycle. It is still born in a nebula, from collapsing gas and dust. Its life will be shorter and its death will be more violent.
As you can see, stars of this size undergo a supernova. As the core is fused to iron, it will continue to gain energy and can even fuse into heavier elements. Eventually, the force that causes the atoms to repel each other will become too strong (the heavier the atom, the stronger the force) and the star will explode, sending elements that are much heavier than iron flying out into space. The remaining core of the star will collapse, becoming a VERY dense material called a Neutron Star. The matter that makes up a Neutron Star is so dense that one tablespoon of it would weigh several billion tons.
There is still one other route that a star could follow during its lifetime.
The life cycle of a giant star, as shown here, is even shorter than the other two illustrations. However, the supernova is such a big explosion that the heaviest elements are formed here. Since the star is so massive, more atoms are able fuse together to form the heaviest elements. In the end, the remaining core is so massive and dense, that its gravitational pull will not even allow light to escape. This is called a black hole.
So, what do you notice about the rate at which a star dies? What about the relationship between mass of the star and mass of the elements produced? In the end, remember that all of the material that makes up your body was once part of a star.
