Stars can turn into black holes without a supernova

As a rule, astronomers believe that stars have to explode in a supernova before they collapse into black holes. That violent death is always the cue, right? Not necessarily. Researchers have spotted a massive star 22 million light years away, N69...

Giant black hole could be to blame for brightest supernova ever

3.8 billion years ago, a star in the southern sky exploded and released 570 billion times more light than our sun and more than twice as much as any other recorded supernova. That star, dubbed ASASSN-15lh, is the brightest supernovae ever observed an...