What causes a supernova:
* Core Collapse: Supernovas primarily occur when a massive star (at least 8 times the mass of our sun) runs out of fuel in its core. This causes the core to collapse under its own gravity.
* Shockwave: This collapse triggers a violent shockwave that travels outward through the star, ripping apart its outer layers.
* Explosion: The shockwave eventually reaches the surface, resulting in a massive explosion, a supernova.
What happens to the outer layers:
* Expelled: The outer layers of the star are ejected into space at incredible speeds, creating a luminous cloud of debris.
* Composition: This debris is rich in elements heavier than hydrogen and helium, which were forged in the star's core during its lifetime.
So, while the explosion involves the outer layers, it's the collapse of the core that triggers the entire event.
It's important to note: Not all stars explode as supernovas. Smaller stars like our sun will eventually expand into red giants and then shed their outer layers as planetary nebulae, leaving behind a white dwarf.
