The core of massive dying galaxies already formed 1.5 billion years after the Big Bang

The most distant dying galaxy discovered so far, more massive than our Milky Way -- with more than a trillion stars -- has revealed that the 'cores' of these systems had formed already 1.5 billion years after the Big Bang, about 1 billion years earlier than previous measurements revealed. The discovery will add to our knowledge on the formation of the Universe more generally, and may cause the computer models astronomers use, one of the most fundamental tools, to be revised.