Thor's Helmet (IMAGE) Arizona State University Caption NGC 2359 (also known as Thor's Helmet) is an emission nebula in the southern constellation Canis Major (The Great Dog). This helmet-shaped cosmic cloud with wing-like appendages is around 15,000 light-years away from Earth and is over 30 light-years across. The central star of Thor's Helmet is the Wolf-Rayet star WR 7. This large, bright star is believed to be about 280,000 times brighter than the Sun, 16 times more massive and 1.41 times larger. It is also in the last stage of its life. Professors Sumner Starrfield, Frank Timmes, and Christian Iliadis will study the pre-explosion evolution of stars like WR 7. Credit ESO/B. Bailleul Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.