Mass decides fate

Weight decides fate

The three stars have 40, 15 and 1 times the mass of the Sun. Mass is the amount of matter in a star, its weight, in a sense. A heavy star has more fuel, but it uses it up much faster. So the heaviest star dies first. While a Sun-like star lives about 12 billion years, the 40-Sun star is finished in about 5 million years.

Why?To keep from being crushed by its own weight, a heavy star has to keep its center much hotter. That means burning through fuel extremely fast. It has 40 times the mass, but it shines hundreds of thousands of times brighter, so its fuel runs out about 2,400 times sooner.

Learn moreHow a star ends depends roughly on its starting mass. Lighter than about 8 Suns: a white dwarf. Heavier: a supernova explosion and a neutron star. Heavier than about 20 to 25 Suns: a black hole. These limits are rough, because they change with how much mass a star loses and how fast it spins. This documentary follows the real order of deaths, starting with the heaviest star.

When

Heavier dies sooner

Star we are watching

Mass: 40 · 15 · 1 times the Sun

Size · state

Life: about 5 million years · 12 million years · 12 billion years