Wonders of the Universe

SUPERNOVA: LIFE CYCLE OF A STAR

All stars are born from clouds of gas, but the length of their life and their eventual fate are governed by their mass (i.e. how much gas they contain). Stars dozens of times heavier than the Sun live for only a few million years before swelling into supergiants and exploding as supernovae (top row). However, stars like the Sun live longer and die more gently, shining steadily for billions of years before swelling into red giants and losing their outer layers as a planetary nebula (middle row). The core of the star, exposed as a white dwarf, then continues to glow for billions of years more before gradually fading out. The least massive stars, the red dwarfs (bottom), simply fade out over tens of billions of years.

Nathalie Lees © HarperCollins