Introducing the Brand New Ultracompact Galaxy

It seems that scientists are discovering young galaxies that are smaller in scale but contain as many stars as a more mature galaxy like the Milky Way:

Tiny Young Galaxies “Full of Stars” Discovered

“While these galaxies are small enough to fit within the central hub of our own Milky Way, they each contain as many stars as larger, more mature galaxies. The light we see from the densely packed galaxies dates to a time when the universe was relatively young, less than three billion years old.

Previously observed tiny galaxies from this time period had correspondingly small numbers of stars. But the newfound galaxies—each only about 5,000 light-years across—weigh in at about 200 billion times the mass of the sun.”