Astronomers have discovered a giant ball of hot gas, billions of light years away, that is radiating the energy of hundreds of billions of suns. The ball may be the most powerful supernova ever seen, a study in the journal Science reports. At the center is an object about 10 miles in diameter that scientists think might be a rare type of star called a magnetar. The gas ball, 3.8 billion light years away, was spotted through the All Sky Automated Survey for Supernovae collaboration. The project, led by researchers at Ohio State University, aims to find supernovae using various small telescopes in the Northern and Southern Hemispheres.