Ring Nebula

Splashery stretches a drumhead over this Splash's outline, twelve inches across, and finds the ways it can ring. Its lowest is 381.7 Hz, 46 cents flat of G4. The next fifteen are its overtones, and each one draws its own figure: sand gathers on the lines that stay still.

Tap it to blow out a new shell of gas.

A planetary nebula is a glowing shell of gas puffed off by a dying star like the Sun. The hot little star left at the middle, a white dwarf, lights up the gas so it glows. The name is an old mistake: through early telescopes these round clouds looked a bit like planets, but they have nothing to do with planets.

This one is shaped like the Ring Nebula, about 2,500 light-years away. Tap it and the star at the middle flares and blows out a thin, bright ring of gas; when it reaches the main ring, the ring glows brighter and is pushed outward, then settles.

This link opens it in the Playground. To put it on your own page, add the element and one script tag. Every option.