DGSAT I is an ultradiffuse galaxy (UDG), meaning it is as big as a galaxy like the Milky Way but its stars are spread out so thinly that it is nearly invisible.
But when scientists saw the ghostly DGSAT 1 in 2016, they noticed that it was sitting all alone, quite unlike other UDGs, which are typically found in clusters.
Its characteristics suggest that the faint object formed during a very different era in the universe, back just 1 billion or so years after the Big Bang, making DGSAT 1 a living fossil.
Source
But when scientists saw the ghostly DGSAT 1 in 2016, they noticed that it was sitting all alone, quite unlike other UDGs, which are typically found in clusters.
Its characteristics suggest that the faint object formed during a very different era in the universe, back just 1 billion or so years after the Big Bang, making DGSAT 1 a living fossil.
Source