Cosmic Evolution

Life Cycle of a Star

Stars are born, they live, and they die. The path they take depends entirely on one thing: Mass.

GAS & DUST

1. Stellar Nebula

A giant cloud of hydrogen gas and dust in space. Gravity pulls the dust and gas together. As the cloud collapses, it spins and heats up, eventually forming a protostar.

Average Mass Path
Massive Mass Path

Average Star

Like our Sun. It fuses hydrogen into helium for billions of years.

~10 Billion Years

Red Giant

Hydrogen runs out. The core collapses, outer layers expand and cool.

Planetary Nebula

Outer layers drift away into space, creating beautiful clouds of gas.

White Dwarf

The hot, dense core remains. Roughly the size of Earth but very heavy.

Eventual fate: Black Dwarf (theoretical)

Massive Star

Burns fuel furiously hot and fast. Blue-white in color.

~10-50 Million Years

Red Supergiant

Expands to massive sizes (Jupiter's orbit!). Fuses heavier elements up to Iron.

Click me!

Supernova

Iron core collapses instantly. A massive explosion brighter than a galaxy.

Neutron Star

High Mass

Dense city-sized ball of neutrons.

Black Hole

Extreme Mass

Gravity so strong light cannot escape.

Stellar Mass Simulator

Drag to change initial mass.

Sun-like Star

A stable yellow star. It will burn for about 10 billion years before turning into a Red Giant.

Mass: 1.0x Sun
Dwarf Sun Giant

Time Travel Simulator

Select a star type and drag through time.

Main Sequence

Currently fusing hydrogen into helium. Stable and warm.

Age: 0 Billion Years
Birth Life Death

Did you know?

We are made of "star stuff." The hydrogen in your body comes from the Big Bang, but the carbon, nitrogen, and oxygen were created inside stars. The iron in your blood was forged in the core of a dying star and scattered by a supernova!