INDEPENDENT, UK - Scientists have been left puzzled by a vast "monster" galaxy that mysteriously went dark.
The web of stars, known as XMM-2599, existed about 12 billion years ago, in the early days of the universe, when it was only about 1.8 billion years old.
It spewed out a vast number of stars in its short life. And then it suddenly stopped.
That rapid and unexplained death has puzzled astronomers, who say the vast galaxy does not fit with our existing models of the early universe.
"Even before the universe was 2 billion years old, XMM-2599 had already formed a mass of more than 300 billion suns, making it an ultramassive galaxy," said Benjamin Forrest, the lead author of the study, in a statement.
"More remarkably, we show that XMM-2599 formed most of its stars in a huge frenzy when the universe was less than 1 billion years old, and then became inactive by the time the universe was only 1.8 billion years old."