At the center of this Hubble Space Telescope image is a Wolf-Rayet star known as WR 31a, located about 30 000 light-years away in the constellation of Carina (The Keel). The blue bubble appearing to encircle WR 31a is a Wolf-Rayet nebula--an interstellar cloud of dust, hydrogen, helium and other gases. Created when stellar winds interact with the outer layers of hydrogen ejected by Wolf簫Rayet stars, these nebulae are frequently ring-shaped or spherical. The bubble is expanding at a rate of around 220,000 kilometers per hour. WR 31a will eventually end its life as a spectacular supernova, and the stellar material expelled from its explosion will later nourish a new generation of stars and planets.