Several newfound galaxies seen as they existed when the universe was young are packed with improbable numbers of stars.
Astronomers don't know what's going on.
The nine galaxies are 11 billion light-years away, which means the light astronomers are looking at left the galaxies 11 billion years ago, when the universe was less than 3 billion years old.
Each of the newly studied galaxies weighs about 200 billion times the mass of the sun yet is a mere 5,000 light-years across. Our Milky Way Galaxy is a fraction of that heft at roughly 3 million times the sun's mass, and yet it stretches across 100,000 light-years of space.
The compact galaxies have been furiously forming stars; each contains as many stars as a typical large galaxy of today, the new observations reveal.
More: http://www.space.com/scienceastronomy/080429-hubble-galaxies.html