Brightest Supernova Ever Seen Pushes Theoretical Models to the Edge

An artist's impression of the record - breakingly powerful, superluminous supernova ASASSN - 15lh as it would appear from an exoplanet located about 10,000 light years away. (Credit: Wayne Rosing) Researchers have discovered the brightest supernova ever seen, and the unusual object powering it could challenge what physicists know about dying stars. When massive stars die, they do not go gently into the night. Instead, they expel most of their mass outward in a powerful explosion called a supernova, leaving behind a glowing cloud of gas and the collapsed remains of the former star’s core. In June 2015, a supernova appeared in the sky over the Southern Hemisphere, and astronomers believe it could mark the death throes of a very unusual star. The supernova, named ASASSN-15lh, was 20 times brighter at its peak than the combined light of the Milky Way galaxy’s 100 billion stars, making it the brightest supernova ever observed. In fact, it’s twice as bright as the previous record-holder.