Emission nebula

Heart Nebula

IC 1805 — a star factory in Cassiopeia

1332 × 3306 px

253 accepted × 20 s (84 min 20 s)

What is it?

A huge cloud of gas where new stars are being born. It’s about 200 light years across.

About 7,500 light years, in the constellation Cassiopeia.

The stars in the centre are only about 1.5 million years old. That’s newborn for a star. Our Sun is 4.6 billion years old.

The red glow is hydrogen gas. Young, very hot stars in the middle blast it with ultraviolet light, and the gas glows red in response.

The dark patches aren’t empty space. They’re thick dust clouds blocking the light behind them.

Behind the photo · optional experiment

Follow ultraviolet energy from young stars into hydrogen gas, then watch visible light leave in new directions.

Journey illustration · not a photograph

Change something. See why.

This experiment changes the physics or the viewpoint. Your photograph stays as the reference observation.

Sources & further reading