WISE J224607.57-052635.0 is the snappy designation of a newly described galaxy, discovered by NASA’s Wide-field Infrared Survey Explorer (WISE) space telescope. While it’s a fairly distant 12.5 billion light years away, it’s visible for one good reason: it’s bright. It’s really bright. It is (or was, 12.5 billion years ago) as bright as 300 trillion suns. This light isn’t being produced by 300 trillion stars, however. At its center is a supermassive black hole surrounded by a gigantic accretion disk; pressure and friction have driven the temperature of the disk to millions of degrees. It’s massively radiating X-rays, which are absorbed by surrounding gas in the galaxy, which then re-radiates in the infra-red.
Interestingly, the luminosity seems to be right on the edge of what theory says is possible. At these scales, the photon pressure from the accretion disk would be so powerful that it would tend to blow the gasses in the disk away, so it should be a self-limiting feature. But this system *seems* to indicate a stable accretion disk radiating more powerfully than it might seem possible. There are some notional explanations for this, however, including a black hole with very slow rotation.