Zombies in space! Supernova turns stars into 'walking dead'

Two inset images showing before-and-after images captured by the Hubble Space Telescope of Supernova 2012Z in the spiral galaxy NGC 1309. The white X at the top of the main image marks the location of the supernova in the galaxy. Astronomers spotted a star system that could have left behind a so-called 'zombie star' after an unusually weak supernova explosion. - EPA

With the help of the Hubble Space Telescope, a team of researchers has spotted a “zombie star” lurking in deep space. What is this astronomical equivalent of the walking dead, and how did it get there?

The story involves a rare type of cosmic explosion, detective work, and a NASA first.