Medium-sized stars like our Sun do not explode, but instead gently shed their outer layers to form glowing planetary nebulae.

These stars lack the mass to fuse carbon. When their helium runs out, the core contracts into a dense white dwarf. This contraction heats the outer layers, causing them to expand and drift away into space. This drifting gas forms a beautiful, expanding cloud called a planetary nebula, leaving behind a slowly cooling core.