Now You See it, Now You Don't: Massive Star Goes Out With a Whimper Instead of a Bang
This pair of visible-light and near-infrared Hubble Space Telescope photos shows the giant star N6946-BH1 before and after it vanished out of sight by imploding to form a black hole. The left image shows the 25 solar mass star as it looked in 2007. In 2009, the star shot up in brightness to become over 1 million times more luminous than our sun for several months. But then it seemed to vanish, as seen in the right panel image from 2015. A small amount of infrared light has been detected from where the star used to be. This radiation probably comes from debris falling onto a black hole. The black hole is located 22 million light-years away in the spiral galaxy NGC 6946.