A star's mass at birth determines its temperature, color, luminosity, and lifespan. Massive stars burn through their fuel fast — a star 20 times the Sun's mass may live only 10 million years. A red dwarf with 0.1 solar masses burns so slowly it can last trillions of years, far longer than the current age of the universe.

This creates a paradox: the biggest, brightest stars are the shortest-lived. The tiny, dim red dwarfs that are barely visible are the most enduring objects in the cosmos. Red dwarfs make up roughly 75% of all stars in the Milky Way.