BellaOnline Forums Education Astronomy WISE finds galaxy brighter than 300 trillion Suns

The most luminous galaxy ever discovered has been found by NASA's WISE (Wide-field Infrared Survey Explorer) space telescope. It's been named WISE J224607.57-052635.0, which isn't a very catchy name. But the galaxy itself is pretty exciting, as it's 12.5 billion light-years away and brighter than 300 trillion Suns.

If WISE J224607.57-052635.0 is 12.5 billion light years away, then we're seeing it as it was 12.5 billion years ago. The Sun is about 4.5 billion years old. That means that the light that WISE is now detecting had already been traveling for eight billion years when our Sun was born.

Astronomers don't think J224607.57-052635.0 actually contained three hundred trillion stars. The Milky Way is a fair-sized galaxy and it has *only* a few hundred billion stars. The enormous luminosity is more likely to be due to the output of a supermassive black hole. (There is evidence of such black holes in most galaxies, including our own.) It looks as though galaxy formation and giant black holes go together in some way, but scientists are still trying to work out that one!

How did this galaxy with its supermassive black hole form in the young Universe? We're seeing it as it was 12.5 billion years ago. But the Universe seems to be only 13.8 billion years old.

The current model proposes that it was about a billion years after the Big Bang that giant nebulae started to form. The first stars and galaxies would form from these giant clouds. It takes time for this to happen and there doesn't seem to have been enough time.

A little puzzle to keep cosmologists busy!