APOD 3.05 Thor's Helmet

Thor's Helmet is the awesome name for NGC 2359. It is an emission nebula, so it radiates light. The other name for Thor's Helmet is the Duck Nebula. The bubble is 30 light years across, made from a Wolf-Rayet star. A Wolf-Rayet star is a rare massive blue giant, which is a star that gives off a solar wind of a few millions of kilometers per hour.

WR stars are at the end of their lifetime, and are thought to be the stars that become supernova.