Star fuses helium to heavier elements, including lithium, beryllium, sodium, calcium, titanium, cobalt, nickel, aluminum, and silicon. Those elements into heavier elements, and so on until iron is formed. Once an iron core is formed and fusion energy outward no longer counters the force of gravity pulling inward. The core collapses in on itself in a fraction of a second. This collapse is followed by an explosion called a super nova.

Super Red Giant to Super Nova