How stars die:

https://futurism.com/

As stars grow they produce more and more heat. The hotter the star becomes, the heavier the elements t creates.iron is created during the life of a star but it is the heaviest element a star can create without dying. Iron doesn't emit enough heat energy against the force of gravity like the other elements do when they react and fuse. This forces the start of the core of the star collapsing. As the nuclear fusion reacts at the core of the star, the star generates more energy while also creating more and more iron. The iron applies great amounts of gravitational pressure to the core of the star. Over perhaps billions of years the star's core eventually collapses. In larger stars this causes a massive explosion of the star itself.
 This explosion is known as a supernova. The supernova produces so much heat that the heavier elements like gold form. All of these elements are spread across the cosmos. The star collapses and destroys itself in an amazing luminous explosion through the galaxies.