Remnants of a star

A Black Hole

After a star dies, it takes many forms and as usual, depending on its size and class. The lower class stars fizzle out into a white dwarf which then  takes billions of years to eventually die. For higher class stars, the core collapses into a neutron star. Sometimes it forms a protostar which has cosmic rays spewing out of both its poles. The biggest stars can collapse under its own gravity and make a black hole.

During the death of lower class stars, they expand into a red giant. These stars can form naturally but are extremely rare. Anyway, there are quite a few of these which used to be like our sun. In fact, out sun will become a red giant in five billion years!

Well that's it, for the whole star topic, I wanted to do the star topic until I thought of a big one. Its going to be theorems about the universe.