Searching for Red Nuggets

I don't understand this but I bet it's really cool.

Astronomers continue to puzzle over the recent discovery of a strange population of dense, compact galaxies that existed in the early universe but are nowhere to be seen today. They suspect the galaxies somehow puffed up into the bloated behemoths we see around us, but new research shortens the timescale during which this mysterious swelling could have happened.

In April, astronomers reported finding extremely compact galaxies as far back as 10 billion years ago, or 3.7 billion years after the big bang. The galaxies contained the same number of stars as modern, blob-shaped galaxies known as ellipticals – but were two to three times smaller on average.

Now, observations have turned up compact galaxies roughly a billion years later, when the universe was almost 5 billion years old. Some, dubbed 'red nuggets', are extremely compact – weighing as much as modern ellipticals, but measuring as little as a tenth their size.

Source: New Scientist