The Hubble Space Telescope took this image of the Stingray Nebula, known to astronomers as Henize 1357. The dim star is surrounded by a halo of gas that was shed when the star became a red giant – a final stage in its life. As the nebula expanded away from the star, the remaining core got hotter and hotter, heating the gas up until it glowed. The Stingray Nebula is the youngest known planetary nebula; it wasn’t visible in the sky just 25 years ago, when the gas around the central star hadn’t heated up enough to glow.