1. A medium sized star starts in a cloud of gas and dust called a .
2. The nebula condenses, gets more dense, the star begins to heat up, and becomes a .
3. Once the star begins fusing hydrogen to helium it starts the process called . The star is now in the stage. Small mass main-sequence stars are , medium mass main-sequence stars are yellow, and high mass main-sequence stars are .
4. After millions, billions, or trillions of years in the main-sequence the star runs out of hydrogen in the core, it begins to burn helium. This heats up the core which expands the star and causes it to cool on the surface. The star has now become a .
5. After a while the star runs out of hydrogen near the core, and has converted all of its helium into carbon at the core. This forms a tiny white hot star made mostly of carbon. This is called a . Also, the layers of gases that made up the surface of the star drift out into space a create a cloud of gas and dust called a .

1. A high mass star starts in a cloud of gas and dust called a .
2. The nebula condenses, gets more dense, the star begins to heat up, and becomes a .
3. Once the star begins fusing hydrogen to helium it starts the process called . The star is now in the . Small mass main-sequence stars are red, medium mass main-sequence stars are yellow, and high mass main-sequence stars are .
4. After millions, billions, or trillions of years in the main-sequence the star runs out of hydrogen in the core, it begins to burn helium. This heats up the core which expands the star and causes it to cool on the surface. The star has now become a .
5. After a while the star runs out of hydrogen near the core. Instead of only forming carbon at the core the star is so big and hot that it forms many different elements in layers all the way up to . Iron has 56 particles in its nucleus. Once it forms iron, the star no longer produces nuclear energy. The star collapses in due to the inward pull of . This creates a huge explosion that gives off as much energy in a single moment as our sun releases in 1 million years. This explosion is called a . During the explosion 66 of the 92 naturally occurring heavy elements are released to space, and the cloud continues outward due to its momentum.
6. After the explosion a destroyed remnant of the iron core is left over. The elements have been smushed into neutrons, forming a . This star is so heavy that 1 sugar cube worth would weigh more than all of the cars on earth.